| /* |
| * Copyright (C) 2011 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package android.widget; |
| |
| import android.content.Context; |
| import android.content.res.TypedArray; |
| import android.graphics.Canvas; |
| import android.graphics.Color; |
| import android.graphics.Paint; |
| import android.graphics.Rect; |
| import android.util.AttributeSet; |
| import android.util.Log; |
| import android.view.Gravity; |
| import android.view.View; |
| import android.view.ViewGroup; |
| import com.android.internal.R.styleable; |
| |
| import java.lang.reflect.Array; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.List; |
| import java.util.Map; |
| |
| import static android.view.View.MeasureSpec.EXACTLY; |
| import static android.view.View.MeasureSpec.UNSPECIFIED; |
| import static java.lang.Math.max; |
| import static java.lang.Math.min; |
| |
| /** |
| * A layout that places its children in a rectangular <em>grid</em>. |
| * <p> |
| * The grid is composed of a set of infinitely thin lines that separate the |
| * viewing area into <em>cells</em>. Throughout the API, grid lines are referenced |
| * by grid <em>indices</em>. A grid with <code>N</code> columns |
| * has <code>N + 1</code> grid indices that run from <code>0</code> |
| * through <code>N</code> inclusive. Regardless of how GridLayout is |
| * configured, grid index <code>0</code> is fixed to the leading edge of the |
| * container and grid index <code>N</code> is fixed to its trailing edge |
| * (after padding is taken into account). |
| * |
| * <h4>Row and Column Groups</h4> |
| * |
| * Children occupy one or more contiguous cells, as defined |
| * by their {@link GridLayout.LayoutParams#rowGroup rowGroup} and |
| * {@link GridLayout.LayoutParams#columnGroup columnGroup} layout parameters. |
| * Each group specifies the set of rows or columns that are to be |
| * occupied; and how children should be aligned within the resulting group of cells. |
| * Although cells do not normally overlap in a GridLayout, GridLayout does |
| * not prevent children being defined to occupy the same cell or group of cells. |
| * In this case however, there is no guarantee that children will not themselves |
| * overlap after the layout operation completes. |
| * |
| * <h4>Default Cell Assignment</h4> |
| * |
| * If no child specifies the row and column indices of the cell it |
| * wishes to occupy, GridLayout assigns cell locations automatically using its: |
| * {@link GridLayout#setOrientation(int) orientation}, |
| * {@link GridLayout#setRowCount(int) rowCount} and |
| * {@link GridLayout#setColumnCount(int) columnCount} properties. |
| * |
| * <h4>Space</h4> |
| * |
| * Space between children may be specified either by using instances of the |
| * dedicated {@link Space} view or by setting the |
| * |
| * {@link ViewGroup.MarginLayoutParams#leftMargin leftMargin}, |
| * {@link ViewGroup.MarginLayoutParams#topMargin topMargin}, |
| * {@link ViewGroup.MarginLayoutParams#rightMargin rightMargin} and |
| * {@link ViewGroup.MarginLayoutParams#bottomMargin bottomMargin} |
| * |
| * layout parameters. When the |
| * {@link GridLayout#setUseDefaultMargins(boolean) useDefaultMargins} |
| * property is set, default margins around children are automatically |
| * allocated based on the child's visual characteristics. Each of the |
| * margins so defined may be independently overridden by an assignment |
| * to the appropriate layout parameter. |
| * |
| * <h4>Excess Space Distribution</h4> |
| * |
| * Like {@link LinearLayout}, a child's ability to stretch is controlled |
| * using <em>weights</em>, which are specified using the |
| * {@link GridLayout.LayoutParams#rowWeight rowWeight} and |
| * {@link GridLayout.LayoutParams#columnWeight columnWeight} layout parameters. |
| * <p> |
| * <p> |
| * See {@link GridLayout.LayoutParams} for a full description of the |
| * layout parameters used by GridLayout. |
| * |
| * @attr ref android.R.styleable#GridLayout_orientation |
| * @attr ref android.R.styleable#GridLayout_rowCount |
| * @attr ref android.R.styleable#GridLayout_columnCount |
| * @attr ref android.R.styleable#GridLayout_useDefaultMargins |
| * @attr ref android.R.styleable#GridLayout_rowOrderPreserved |
| * @attr ref android.R.styleable#GridLayout_columnOrderPreserved |
| */ |
| public class GridLayout extends ViewGroup { |
| |
| // Public constants |
| |
| /** |
| * The horizontal orientation. |
| */ |
| public static final int HORIZONTAL = LinearLayout.HORIZONTAL; |
| |
| /** |
| * The vertical orientation. |
| */ |
| public static final int VERTICAL = LinearLayout.VERTICAL; |
| |
| /** |
| * The constant used to indicate that a value is undefined. |
| * Fields can use this value to indicate that their values |
| * have not yet been set. Similarly, methods can return this value |
| * to indicate that there is no suitable value that the implementation |
| * can return. |
| * The value used for the constant (currently {@link Integer#MIN_VALUE}) is |
| * intended to avoid confusion between valid values whose sign may not be known. |
| */ |
| public static final int UNDEFINED = Integer.MIN_VALUE; |
| |
| // Misc constants |
| |
| private static final String TAG = GridLayout.class.getName(); |
| private static final boolean DEBUG = false; |
| private static final Paint GRID_PAINT = new Paint(); |
| private static final double GOLDEN_RATIO = (1 + Math.sqrt(5)) / 2; |
| private static final int MIN = 0; |
| private static final int PRF = 1; |
| private static final int MAX = 2; |
| |
| // Defaults |
| |
| private static final int DEFAULT_ORIENTATION = HORIZONTAL; |
| private static final int DEFAULT_COUNT = UNDEFINED; |
| private static final boolean DEFAULT_USE_DEFAULT_MARGINS = false; |
| private static final boolean DEFAULT_ORDER_PRESERVED = false; |
| private static final boolean DEFAULT_MARGINS_INCLUDED = true; |
| // todo remove this |
| private static final int DEFAULT_CONTAINER_MARGIN = 20; |
| |
| // TypedArray indices |
| |
| private static final int ORIENTATION = styleable.GridLayout_orientation; |
| private static final int ROW_COUNT = styleable.GridLayout_rowCount; |
| private static final int COLUMN_COUNT = styleable.GridLayout_columnCount; |
| private static final int USE_DEFAULT_MARGINS = styleable.GridLayout_useDefaultMargins; |
| private static final int MARGINS_INCLUDED = styleable.GridLayout_marginsIncludedInAlignment; |
| private static final int ROW_ORDER_PRESERVED = styleable.GridLayout_rowOrderPreserved; |
| private static final int COLUMN_ORDER_PRESERVED = styleable.GridLayout_columnOrderPreserved; |
| |
| // Static initialization |
| |
| static { |
| GRID_PAINT.setColor(Color.argb(50, 255, 255, 255)); |
| } |
| |
| // Instance variables |
| |
| private final Axis mHorizontalAxis = new Axis(true); |
| private final Axis mVerticalAxis = new Axis(false); |
| private boolean mLayoutParamsValid = false; |
| private int mOrientation = DEFAULT_ORIENTATION; |
| private boolean mUseDefaultMargins = DEFAULT_USE_DEFAULT_MARGINS; |
| private boolean mMarginsIncludedInAlignment = DEFAULT_MARGINS_INCLUDED; |
| private int mDefaultGravity = Gravity.NO_GRAVITY; |
| |
| /* package */ boolean accommodateBothMinAndMax = false; |
| |
| // Constructors |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public GridLayout(Context context) { |
| super(context); |
| if (DEBUG) { |
| setWillNotDraw(false); |
| } |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public GridLayout(Context context, AttributeSet attrs, int defStyle) { |
| super(context, attrs, defStyle); |
| processAttributes(context, attrs); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public GridLayout(Context context, AttributeSet attrs) { |
| super(context, attrs); |
| processAttributes(context, attrs); |
| } |
| |
| private void processAttributes(Context context, AttributeSet attrs) { |
| TypedArray a = context.obtainStyledAttributes(attrs, styleable.GridLayout); |
| try { |
| setRowCount(a.getInteger(ROW_COUNT, DEFAULT_COUNT)); |
| setColumnCount(a.getInteger(COLUMN_COUNT, DEFAULT_COUNT)); |
| mOrientation = a.getInteger(ORIENTATION, DEFAULT_ORIENTATION); |
| mUseDefaultMargins = a.getBoolean(USE_DEFAULT_MARGINS, DEFAULT_USE_DEFAULT_MARGINS); |
| mMarginsIncludedInAlignment = a.getBoolean(MARGINS_INCLUDED, DEFAULT_MARGINS_INCLUDED); |
| setRowOrderPreserved(a.getBoolean(ROW_ORDER_PRESERVED, DEFAULT_ORDER_PRESERVED)); |
| setColumnOrderPreserved(a.getBoolean(COLUMN_ORDER_PRESERVED, DEFAULT_ORDER_PRESERVED)); |
| } finally { |
| a.recycle(); |
| } |
| } |
| |
| // Implementation |
| |
| /** |
| * Returns the current orientation. |
| * |
| * @return either {@link #HORIZONTAL} or {@link #VERTICAL}. The default |
| * is {@link #HORIZONTAL}. |
| * |
| * @see #setOrientation(int) |
| * |
| * @attr ref android.R.styleable#GridLayout_orientation |
| */ |
| public int getOrientation() { |
| return mOrientation; |
| } |
| |
| /** |
| * The orientation property does not affect layout. Orientation is used |
| * only to generate default row/column indices when they are not specified |
| * by a component's layout parameters. |
| * |
| * @param orientation the orientation, either {@link #HORIZONTAL} or {@link #VERTICAL}. |
| * |
| * @see #getOrientation() |
| * |
| * @attr ref android.R.styleable#GridLayout_orientation |
| */ |
| public void setOrientation(int orientation) { |
| if (mOrientation != orientation) { |
| mOrientation = orientation; |
| requestLayout(); |
| } |
| } |
| |
| /** |
| * Returns the current number of rows. This is either the last value that was set |
| * with {@link #setRowCount(int)} or, if no such value was set, the maximum |
| * value of each the upper bounds defined in {@link LayoutParams#rowGroup}. |
| * |
| * @return the current number of rows |
| * |
| * @see #setRowCount(int) |
| * @see LayoutParams#rowGroup |
| * |
| * @attr ref android.R.styleable#GridLayout_rowCount |
| */ |
| public int getRowCount() { |
| return mVerticalAxis.getCount(); |
| } |
| |
| /** |
| * The rowCount property does not affect layout. RowCount is used |
| * only to generate default row/column indices when they are not specified |
| * by a component's layout parameters. |
| * |
| * @param rowCount the number of rows. |
| * |
| * @see #getRowCount() |
| * @see LayoutParams#rowGroup |
| * |
| * @attr ref android.R.styleable#GridLayout_rowCount |
| */ |
| public void setRowCount(int rowCount) { |
| mVerticalAxis.setCount(rowCount); |
| } |
| |
| /** |
| * Returns the current number of columns. This is either the last value that was set |
| * with {@link #setColumnCount(int)} or, if no such value was set, the maximum |
| * value of each the upper bounds defined in {@link LayoutParams#columnGroup}. |
| * |
| * @return the current number of columns |
| * |
| * @see #setColumnCount(int) |
| * @see LayoutParams#columnGroup |
| * |
| * @attr ref android.R.styleable#GridLayout_columnCount |
| */ |
| public int getColumnCount() { |
| return mHorizontalAxis.getCount(); |
| } |
| |
| /** |
| * The columnCount property does not affect layout. ColumnCount is used |
| * only to generate default column/column indices when they are not specified |
| * by a component's layout parameters. |
| * |
| * @param columnCount the number of columns. |
| * |
| * @see #getColumnCount() |
| * @see LayoutParams#columnGroup |
| * |
| * @attr ref android.R.styleable#GridLayout_columnCount |
| */ |
| public void setColumnCount(int columnCount) { |
| mHorizontalAxis.setCount(columnCount); |
| } |
| |
| /** |
| * Returns whether or not this GridLayout will allocate default margins when no |
| * corresponding layout parameters are defined. |
| * |
| * @return true if default margins should be allocated. |
| * |
| * @see #setUseDefaultMargins(boolean) |
| * |
| * @attr ref android.R.styleable#GridLayout_useDefaultMargins |
| */ |
| public boolean getUseDefaultMargins() { |
| return mUseDefaultMargins; |
| } |
| |
| /** |
| * When true, GridLayout allocates default margins around children |
| * based on the child's visual characteristics. Each of the |
| * margins so defined may be independently overridden by an assignment |
| * to the appropriate layout parameter. |
| * <p> |
| * When false, the default value of all margins is zero. |
| * <p> |
| * When setting to true, consider setting the value of the |
| * {@link #setMarginsIncludedInAlignment(boolean) marginsIncludedInAlignment} |
| * property to false. |
| * |
| * @param useDefaultMargins use true to make GridLayout allocate default margins |
| * |
| * @see #getUseDefaultMargins() |
| * @see #setMarginsIncludedInAlignment(boolean) |
| * |
| * @see MarginLayoutParams#leftMargin |
| * @see MarginLayoutParams#topMargin |
| * @see MarginLayoutParams#rightMargin |
| * @see MarginLayoutParams#bottomMargin |
| * |
| * @attr ref android.R.styleable#GridLayout_useDefaultMargins |
| */ |
| public void setUseDefaultMargins(boolean useDefaultMargins) { |
| mUseDefaultMargins = useDefaultMargins; |
| requestLayout(); |
| } |
| |
| /** |
| * Returns whether GridLayout aligns the edges of the view or the edges |
| * of the larger rectangle created by extending the view by its associated |
| * margins. |
| * |
| * @see #setMarginsIncludedInAlignment(boolean) |
| * |
| * @return true if alignment is between edges including margins. |
| * |
| * @attr ref android.R.styleable#GridLayout_marginsIncludedInAlignment |
| */ |
| public boolean getMarginsIncludedInAlignment() { |
| return mMarginsIncludedInAlignment; |
| } |
| |
| /** |
| * When true, the bounds of a view are extended outwards according to its |
| * margins before the edges of the resulting rectangle are aligned. |
| * When false, alignment occurs between the bounds of the view - i.e. |
| * {@link #LEFT} alignment means align the left edges of the view. |
| * |
| * @param marginsIncludedInAlignment true if alignment is between edges including margins. |
| * |
| * @see #getMarginsIncludedInAlignment() |
| * |
| * @attr ref android.R.styleable#GridLayout_marginsIncludedInAlignment |
| */ |
| public void setMarginsIncludedInAlignment(boolean marginsIncludedInAlignment) { |
| mMarginsIncludedInAlignment = marginsIncludedInAlignment; |
| requestLayout(); |
| } |
| |
| /** |
| * Returns whether or not row boundaries are ordered by their grid indices. |
| * |
| * @return true if row boundaries must appear in the order of their indices, false otherwise. |
| * The default is false. |
| * |
| * @see #setRowOrderPreserved(boolean) |
| * |
| * @attr ref android.R.styleable#GridLayout_rowOrderPreserved |
| */ |
| public boolean isRowOrderPreserved() { |
| return mVerticalAxis.isOrderPreserved(); |
| } |
| |
| /** |
| * When this property is <code>false</code>, the default state, GridLayout |
| * is at liberty to choose an order that better suits the heights of its children. |
| <p> |
| * When this property is <code>true</code>, GridLayout is forced to place the row boundaries |
| * so that their associated grid indices are in ascending order in the view. |
| * <p> |
| * GridLayout implements this specification by creating ordering constraints between |
| * the variables that represent the locations of the row boundaries. |
| * |
| * When this property is <code>true</code>, constraints are added for each pair of consecutive |
| * indices: i.e. between row boundaries: <code>[0..1], [1..2], [3..4],...</code> etc. |
| * |
| * When the property is <code>false</code>, the ordering constraints are placed |
| * only between boundaries that separate opposing edges of the layout's children. |
| * |
| * @param rowOrderPreserved use true to force GridLayout to respect the order |
| * of row boundaries. |
| * |
| * @see #isRowOrderPreserved() |
| * |
| * @attr ref android.R.styleable#GridLayout_rowOrderPreserved |
| */ |
| public void setRowOrderPreserved(boolean rowOrderPreserved) { |
| mVerticalAxis.setOrderPreserved(rowOrderPreserved); |
| invalidateStructure(); |
| requestLayout(); |
| } |
| |
| /** |
| * Returns whether or not column boundaries are ordered by their grid indices. |
| * |
| * @return true if column boundaries must appear in the order of their indices, false otherwise. |
| * The default is false. |
| * |
| * @see #setColumnOrderPreserved(boolean) |
| * |
| * @attr ref android.R.styleable#GridLayout_columnOrderPreserved |
| */ |
| public boolean isColumnOrderPreserved() { |
| return mHorizontalAxis.isOrderPreserved(); |
| } |
| |
| /** |
| * When this property is <code>false</code>, the default state, GridLayout |
| * is at liberty to choose an order that better suits the widths of its children. |
| <p> |
| * When this property is <code>true</code>, GridLayout is forced to place the column boundaries |
| * so that their associated grid indices are in ascending order in the view. |
| * <p> |
| * GridLayout implements this specification by creating ordering constraints between |
| * the variables that represent the locations of the column boundaries. |
| * |
| * When this property is <code>true</code>, constraints are added for each pair of consecutive |
| * indices: i.e. between column boundaries: <code>[0..1], [1..2], [3..4],...</code> etc. |
| * |
| * When the property is <code>false</code>, the ordering constraints are placed |
| * only between boundaries that separate opposing edges of the layout's children. |
| * |
| * @param columnOrderPreserved use true to force GridLayout to respect the order |
| * of column boundaries. |
| * |
| * @see #isColumnOrderPreserved() |
| * |
| * @attr ref android.R.styleable#GridLayout_columnOrderPreserved |
| */ |
| public void setColumnOrderPreserved(boolean columnOrderPreserved) { |
| mHorizontalAxis.setOrderPreserved(columnOrderPreserved); |
| invalidateStructure(); |
| requestLayout(); |
| } |
| |
| private static int sum(float[] a) { |
| int result = 0; |
| for (int i = 0, length = a.length; i < length; i++) { |
| result += a[i]; |
| } |
| return result; |
| } |
| |
| private int getDefaultMargin(View c, boolean leading, boolean horizontal) { |
| // In the absence of any other information, calculate a default gap such |
| // that, in a grid of identical components, the heights and the vertical |
| // gaps are in the proportion of the golden ratio. |
| // To effect this with equal margins at each edge, set each of the |
| // four margin values to half this amount. |
| return (int) (c.getMeasuredHeight() / GOLDEN_RATIO / 2); |
| } |
| |
| private int getDefaultMargin(View c, boolean isAtEdge, boolean leading, boolean horizontal) { |
| // todo remove DEFAULT_CONTAINER_MARGIN. Use padding? Seek advice on Themes/Styles, etc. |
| return isAtEdge ? DEFAULT_CONTAINER_MARGIN : getDefaultMargin(c, leading, horizontal); |
| } |
| |
| private int getDefaultMarginValue(View c, LayoutParams p, boolean leading, boolean horizontal) { |
| if (!mUseDefaultMargins) { |
| return 0; |
| } |
| Group group = horizontal ? p.columnGroup : p.rowGroup; |
| Axis axis = horizontal ? mHorizontalAxis : mVerticalAxis; |
| Interval span = group.span; |
| boolean isAtEdge = leading ? (span.min == 0) : (span.max == axis.getCount()); |
| |
| return getDefaultMargin(c, isAtEdge, leading, horizontal); |
| } |
| |
| private int getMargin(View view, boolean leading, boolean horizontal) { |
| LayoutParams lp = getLayoutParams(view); |
| int margin = horizontal ? |
| (leading ? lp.leftMargin : lp.rightMargin) : |
| (leading ? lp.topMargin : lp.bottomMargin); |
| return margin == UNDEFINED ? getDefaultMarginValue(view, lp, leading, horizontal) : margin; |
| } |
| |
| private static boolean isUndefined(Interval span) { |
| return span.min == UNDEFINED || span.max == UNDEFINED; |
| } |
| |
| private void validateLayoutParams() { |
| // install default indices for cells if *none* are defined |
| if (mHorizontalAxis.maxIndex1() == UNDEFINED || (mVerticalAxis.maxIndex1() == UNDEFINED)) { |
| boolean horizontal = mOrientation == HORIZONTAL; |
| int count = horizontal ? mHorizontalAxis.count : mVerticalAxis.count; |
| if (count == UNDEFINED) { |
| count = Integer.MAX_VALUE; |
| } |
| int x = 0; |
| int y = 0; |
| int maxSize = 0; |
| for (int i = 0, size = getChildCount(); i < size; i++) { |
| LayoutParams lp = getLayoutParams1(getChildAt(i)); |
| |
| Interval hSpan = lp.columnGroup.span; |
| int cellWidth = hSpan.size(); |
| |
| Interval vSpan = lp.rowGroup.span; |
| int cellHeight = vSpan.size(); |
| |
| if (horizontal) { |
| if (x + cellWidth > count) { |
| x = 0; |
| y += maxSize; |
| maxSize = 0; |
| } |
| } else { |
| if (y + cellHeight > count) { |
| y = 0; |
| x += maxSize; |
| maxSize = 0; |
| } |
| } |
| lp.setHorizontalGroupSpan(new Interval(x, x + cellWidth)); |
| lp.setVerticalGroupSpan(new Interval(y, y + cellHeight)); |
| |
| if (horizontal) { |
| x = x + cellWidth; |
| } else { |
| y = y + cellHeight; |
| } |
| maxSize = max(maxSize, horizontal ? cellHeight : cellWidth); |
| } |
| } else { |
| /* |
| At least one row and one column index have been defined. |
| Assume missing row/cols are in error and set them to zero so that |
| they will display top/left and the developer can add the right indices. |
| Without this UNDEFINED would cause ArrayIndexOutOfBoundsException. |
| */ |
| for (int i = 0, size = getChildCount(); i < size; i++) { |
| LayoutParams lp = getLayoutParams1(getChildAt(i)); |
| if (isUndefined(lp.columnGroup.span)) { |
| lp.setHorizontalGroupSpan(LayoutParams.DEFAULT_SPAN); |
| } |
| if (isUndefined(lp.rowGroup.span)) { |
| lp.setVerticalGroupSpan(LayoutParams.DEFAULT_SPAN); |
| } |
| } |
| } |
| } |
| |
| private void invalidateStructure() { |
| mLayoutParamsValid = false; |
| mHorizontalAxis.invalidateStructure(); |
| mVerticalAxis.invalidateStructure(); |
| // This can end up being done twice. But better that than not at all. |
| invalidateValues(); |
| } |
| |
| private void invalidateValues() { |
| // Need null check because requestLayout() is called in View's initializer, |
| // before we are set up. |
| if (mHorizontalAxis != null && mVerticalAxis != null) { |
| mHorizontalAxis.invalidateValues(); |
| mVerticalAxis.invalidateValues(); |
| } |
| } |
| |
| private LayoutParams getLayoutParams1(View c) { |
| return (LayoutParams) c.getLayoutParams(); |
| } |
| |
| private LayoutParams getLayoutParams(View c) { |
| if (!mLayoutParamsValid) { |
| validateLayoutParams(); |
| mLayoutParamsValid = true; |
| } |
| return getLayoutParams1(c); |
| } |
| |
| @Override |
| protected LayoutParams generateDefaultLayoutParams() { |
| return new LayoutParams(); |
| } |
| |
| @Override |
| public LayoutParams generateLayoutParams(AttributeSet attrs) { |
| return new LayoutParams(getContext(), attrs, mDefaultGravity); |
| } |
| |
| @Override |
| protected LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) { |
| return new LayoutParams(p); |
| } |
| |
| // Draw grid |
| |
| private void drawLine(Canvas graphics, int x1, int y1, int x2, int y2, Paint paint) { |
| int dx = getPaddingLeft(); |
| int dy = getPaddingTop(); |
| graphics.drawLine(dx + x1, dy + y1, dx + x2, dy + y2, paint); |
| } |
| |
| @Override |
| protected void onDraw(Canvas canvas) { |
| super.onDraw(canvas); |
| |
| if (DEBUG) { |
| int height = getHeight() - getPaddingTop() - getPaddingBottom(); |
| int width = getWidth() - getPaddingLeft() - getPaddingRight(); |
| |
| int[] xs = mHorizontalAxis.locations; |
| for (int i = 0, length = xs.length; i < length; i++) { |
| int x = xs[i]; |
| drawLine(canvas, x, 0, x, height - 1, GRID_PAINT); |
| } |
| int[] ys = mVerticalAxis.locations; |
| for (int i = 0, length = ys.length; i < length; i++) { |
| int y = ys[i]; |
| drawLine(canvas, 0, y, width - 1, y, GRID_PAINT); |
| } |
| } |
| } |
| |
| // Add/remove |
| |
| @Override |
| public void addView(View child, int index, ViewGroup.LayoutParams params) { |
| super.addView(child, index, params); |
| invalidateStructure(); |
| } |
| |
| @Override |
| public void removeView(View view) { |
| super.removeView(view); |
| invalidateStructure(); |
| } |
| |
| @Override |
| public void removeViewInLayout(View view) { |
| super.removeViewInLayout(view); |
| invalidateStructure(); |
| } |
| |
| @Override |
| public void removeViewsInLayout(int start, int count) { |
| super.removeViewsInLayout(start, count); |
| invalidateStructure(); |
| } |
| |
| @Override |
| public void removeViewAt(int index) { |
| super.removeViewAt(index); |
| invalidateStructure(); |
| } |
| |
| // Measurement |
| |
| private static int getChildMeasureSpec2(int spec, int padding, int childDimension) { |
| int resultSize; |
| int resultMode; |
| |
| if (childDimension >= 0) { |
| resultSize = childDimension; |
| resultMode = EXACTLY; |
| } else { |
| /* |
| using the following lines would replicate the logic of ViewGroup.getChildMeasureSpec() |
| |
| int specMode = MeasureSpec.getMode(spec); |
| int specSize = MeasureSpec.getSize(spec); |
| int size = Math.max(0, specSize - padding); |
| |
| resultSize = size; |
| resultMode = (specMode == EXACTLY && childDimension == LayoutParams.WRAP_CONTENT) ? |
| AT_MOST : specMode; |
| */ |
| resultSize = 0; |
| resultMode = UNSPECIFIED; |
| } |
| return MeasureSpec.makeMeasureSpec(resultSize, resultMode); |
| } |
| |
| @Override |
| protected void measureChild(View child, int parentWidthSpec, int parentHeightSpec) { |
| ViewGroup.LayoutParams lp = child.getLayoutParams(); |
| |
| int childWidthMeasureSpec = getChildMeasureSpec2(parentWidthSpec, |
| mPaddingLeft + mPaddingRight, lp.width); |
| int childHeightMeasureSpec = getChildMeasureSpec2(parentHeightSpec, |
| mPaddingTop + mPaddingBottom, lp.height); |
| |
| child.measure(childWidthMeasureSpec, childHeightMeasureSpec); |
| } |
| |
| @Override |
| protected void onMeasure(int widthSpec, int heightSpec) { |
| measureChildren(widthSpec, heightSpec); |
| |
| int computedWidth = getPaddingLeft() + mHorizontalAxis.getMin() + getPaddingRight(); |
| int computedHeight = getPaddingTop() + mVerticalAxis.getMin() + getPaddingBottom(); |
| |
| setMeasuredDimension( |
| resolveSizeAndState(computedWidth, widthSpec, 0), |
| resolveSizeAndState(computedHeight, heightSpec, 0)); |
| } |
| |
| private int protect(int alignment) { |
| return (alignment == UNDEFINED) ? 0 : alignment; |
| } |
| |
| private int getMeasurement(View c, boolean horizontal, int measurementType) { |
| return horizontal ? c.getMeasuredWidth() : c.getMeasuredHeight(); |
| } |
| |
| private int getMeasurementIncludingMargin(View c, boolean horizontal, int measurementType) { |
| int result = getMeasurement(c, horizontal, measurementType); |
| if (mMarginsIncludedInAlignment) { |
| int leadingMargin = getMargin(c, true, horizontal); |
| int trailingMargin = getMargin(c, false, horizontal); |
| return result + leadingMargin + trailingMargin; |
| } |
| return result; |
| } |
| |
| private int getAlignmentValue(Alignment alignment, View c, int dim, boolean horizontal, View c1) { |
| int result = alignment.getAlignmentValue(c, dim); |
| if (mMarginsIncludedInAlignment) { |
| int leadingMargin = getMargin(c1, true, horizontal); |
| return result + leadingMargin; |
| } |
| return result; |
| } |
| |
| @Override |
| public void requestLayout() { |
| super.requestLayout(); |
| invalidateValues(); |
| } |
| |
| // Layout container |
| |
| /** |
| * {@inheritDoc} |
| */ |
| /* |
| The layout operation is implemented by delegating the heavy lifting to the |
| to the mHorizontalAxis and mVerticalAxis instances of the internal Axis class. |
| Together they compute the locations of the vertical and horizontal lines of |
| the grid (respectively!). |
| |
| This method is then left with the simpler task of applying margins, gravity |
| and sizing to each child view and then placing it in its cell. |
| */ |
| @Override |
| protected void onLayout(boolean changed, int l, int t, int r, int b) { |
| int targetWidth = r - l; |
| int targetHeight = b - t; |
| |
| int paddingLeft = getPaddingLeft(); |
| int paddingTop = getPaddingTop(); |
| int paddingRight = getPaddingRight(); |
| int paddingBottom = getPaddingBottom(); |
| |
| mHorizontalAxis.layout(targetWidth - paddingLeft - paddingRight); |
| mVerticalAxis.layout(targetHeight - paddingTop - paddingBottom); |
| |
| for (int i = 0, size = getChildCount(); i < size; i++) { |
| View view = getChildAt(i); |
| LayoutParams lp = getLayoutParams(view); |
| Group columnGroup = lp.columnGroup; |
| Group rowGroup = lp.rowGroup; |
| |
| Interval colSpan = columnGroup.span; |
| Interval rowSpan = rowGroup.span; |
| |
| int x1 = mHorizontalAxis.getLocationIncludingMargin(view, true, colSpan.min); |
| int y1 = mVerticalAxis.getLocationIncludingMargin(view, true, rowSpan.min); |
| |
| int x2 = mHorizontalAxis.getLocationIncludingMargin(view, false, colSpan.max); |
| int y2 = mVerticalAxis.getLocationIncludingMargin(view, false, rowSpan.max); |
| |
| int cellWidth = x2 - x1; |
| int cellHeight = y2 - y1; |
| |
| int pWidth = getMeasurement(view, true, PRF); |
| int pHeight = getMeasurement(view, false, PRF); |
| |
| Alignment hAlignment = columnGroup.alignment; |
| Alignment vAlignment = rowGroup.alignment; |
| |
| int dx, dy; |
| |
| if (mMarginsIncludedInAlignment) { |
| dx = protect(hAlignment.getAlignmentValue(view, cellWidth - pWidth)); |
| dy = protect(vAlignment.getAlignmentValue(view, cellHeight - pHeight)); |
| } else { |
| Bounds colBounds = mHorizontalAxis.getGroupBounds().getValue(i); |
| Bounds rowBounds = mVerticalAxis.getGroupBounds().getValue(i); |
| |
| int mx = protect(hAlignment.getAlignmentValue(null, cellWidth - colBounds.size())); |
| int my = protect(vAlignment.getAlignmentValue(null, cellHeight - rowBounds.size())); |
| |
| dx = mx + -colBounds.below - hAlignment.getAlignmentValue(view, pWidth); |
| dy = my + -rowBounds.below - vAlignment.getAlignmentValue(view, pHeight); |
| } |
| |
| int width = hAlignment.getSizeInCell(view, pWidth, cellWidth); |
| int height = vAlignment.getSizeInCell(view, pHeight, cellHeight); |
| |
| int cx = paddingLeft + x1 + dx; |
| int cy = paddingTop + y1 + dy; |
| view.layout(cx, cy, cx + width, cy + height); |
| } |
| } |
| |
| // Inner classes |
| |
| /* |
| This internal class houses the algorithm for computing the locations of grid lines; |
| along either the horizontal or vertical axis. A GridLayout uses two instances of this class - |
| distinguished by the "horizontal" flag which is true for the horizontal axis and false |
| for the vertical one. |
| */ |
| private class Axis { |
| private static final int MIN_VALUE = -1000000; |
| |
| private static final int UNVISITED = 0; |
| private static final int PENDING = 1; |
| private static final int COMPLETE = 2; |
| |
| public final boolean horizontal; |
| |
| public int count = UNDEFINED; |
| public boolean countValid = false; |
| public boolean countWasExplicitySet = false; |
| |
| PackedMap<Group, Bounds> groupBounds; |
| public boolean groupBoundsValid = false; |
| |
| PackedMap<Interval, MutableInt> spanSizes; |
| public boolean spanSizesValid = false; |
| |
| public int[] leadingMargins; |
| public boolean leadingMarginsValid = false; |
| |
| public int[] trailingMargins; |
| public boolean trailingMarginsValid = false; |
| |
| public Arc[] arcs; |
| public boolean arcsValid = false; |
| |
| public int[] minima; |
| public boolean minimaValid = false; |
| |
| public float[] weights; |
| public int[] locations; |
| |
| private boolean mOrderPreserved = DEFAULT_ORDER_PRESERVED; |
| |
| private Axis(boolean horizontal) { |
| this.horizontal = horizontal; |
| } |
| |
| private int maxIndex(boolean internal) { |
| // note the number Integer.MIN_VALUE + 1 comes up in undefined cells |
| int count = -1; |
| for (int i = 0, size = getChildCount(); i < size; i++) { |
| LayoutParams params = internal ? |
| getLayoutParams1(getChildAt(i)) : |
| getLayoutParams(getChildAt(i)); |
| Group g = horizontal ? params.columnGroup : params.rowGroup; |
| count = max(count, g.span.min); |
| count = max(count, g.span.max); |
| } |
| return count == -1 ? UNDEFINED : count; |
| } |
| |
| private int maxIndex1() { |
| return maxIndex(true); |
| } |
| |
| public int getCount() { |
| if (!countWasExplicitySet && !countValid) { |
| count = max(0, maxIndex(false)); // if there are no cells, the count is zero |
| countValid = true; |
| } |
| return count; |
| } |
| |
| public void setCount(int count) { |
| this.count = count; |
| this.countWasExplicitySet = count != UNDEFINED; |
| } |
| |
| public boolean isOrderPreserved() { |
| return mOrderPreserved; |
| } |
| |
| public void setOrderPreserved(boolean orderPreserved) { |
| mOrderPreserved = orderPreserved; |
| invalidateStructure(); |
| } |
| |
| private PackedMap<Group, Bounds> createGroupBounds() { |
| int N = getChildCount(); |
| Group[] groups = new Group[N]; |
| Bounds[] bounds = new Bounds[N]; |
| for (int i = 0; i < N; i++) { |
| LayoutParams lp = getLayoutParams(getChildAt(i)); |
| Group group = horizontal ? lp.columnGroup : lp.rowGroup; |
| |
| groups[i] = group; |
| bounds[i] = new Bounds(); |
| } |
| |
| return new PackedMap<Group, Bounds>(groups, bounds); |
| } |
| |
| private void computeGroupBounds() { |
| for (int i = 0; i < groupBounds.values.length; i++) { |
| groupBounds.values[i].reset(); |
| } |
| for (int i = 0, N = getChildCount(); i < N; i++) { |
| View c = getChildAt(i); |
| LayoutParams lp = getLayoutParams(c); |
| Group g = horizontal ? lp.columnGroup : lp.rowGroup; |
| |
| Bounds bounds = groupBounds.getValue(i); |
| |
| int size = getMeasurementIncludingMargin(c, horizontal, PRF); |
| // todo test this works correctly when the returned value is UNDEFINED |
| int below = getAlignmentValue(g.alignment, c, size, horizontal, c); |
| bounds.include(-below, size - below); |
| } |
| } |
| |
| private PackedMap<Group, Bounds> getGroupBounds() { |
| if (groupBounds == null) { |
| groupBounds = createGroupBounds(); |
| } |
| if (!groupBoundsValid) { |
| computeGroupBounds(); |
| groupBoundsValid = true; |
| } |
| return groupBounds; |
| } |
| |
| // Add values computed by alignment - taking the max of all alignments in each span |
| private PackedMap<Interval, MutableInt> createSpanSizes() { |
| PackedMap<Group, Bounds> groupBounds = getGroupBounds(); |
| int N = groupBounds.keys.length; |
| Interval[] spans = new Interval[N]; |
| MutableInt[] values = new MutableInt[N]; |
| for (int i = 0; i < N; i++) { |
| Interval key = groupBounds.keys[i].span; |
| |
| spans[i] = key; |
| values[i] = new MutableInt(); |
| } |
| return new PackedMap<Interval, MutableInt>(spans, values); |
| } |
| |
| private void computeSpanSizes() { |
| MutableInt[] spans = spanSizes.values; |
| for (int i = 0; i < spans.length; i++) { |
| spans[i].reset(); |
| } |
| |
| Bounds[] bounds = getGroupBounds().values; // use getter to trigger a re-evaluation |
| for (int i = 0; i < bounds.length; i++) { |
| int value = bounds[i].size(); |
| |
| MutableInt valueHolder = spanSizes.getValue(i); |
| valueHolder.value = max(valueHolder.value, value); |
| } |
| } |
| |
| private PackedMap<Interval, MutableInt> getSpanSizes() { |
| if (spanSizes == null) { |
| spanSizes = createSpanSizes(); |
| } |
| if (!spanSizesValid) { |
| computeSpanSizes(); |
| spanSizesValid = true; |
| } |
| return spanSizes; |
| } |
| |
| private void include(List<Arc> arcs, Interval key, MutableInt size) { |
| // this bit below should really be computed outside here - |
| // its just to stop default (col>0) constraints obliterating valid entries |
| for (Arc arc : arcs) { |
| Interval span = arc.span; |
| if (span.equals(key)) { |
| return; |
| } |
| } |
| arcs.add(new Arc(key, size)); |
| } |
| |
| private void include2(List<Arc> arcs, Interval span, MutableInt min, MutableInt max, |
| boolean both) { |
| include(arcs, span, min); |
| if (both) { |
| // todo |
| // include(arcs, span.inverse(), max.neg()); |
| } |
| } |
| |
| private void include2(List<Arc> arcs, Interval span, int min, int max, boolean both) { |
| include2(arcs, span, new MutableInt(min), new MutableInt(max), both); |
| } |
| |
| // Group arcs by their first vertex, returning an array of arrays. |
| // This is linear in the number of arcs. |
| private Arc[][] groupArcsByFirstVertex(Arc[] arcs) { |
| int N = getCount() + 1;// the number of vertices |
| Arc[][] result = new Arc[N][]; |
| int[] sizes = new int[N]; |
| for (Arc arc : arcs) { |
| sizes[arc.span.min]++; |
| } |
| for (int i = 0; i < sizes.length; i++) { |
| result[i] = new Arc[sizes[i]]; |
| } |
| // reuse the sizes array to hold the current last elements as we insert each arc |
| Arrays.fill(sizes, 0); |
| for (Arc arc : arcs) { |
| int i = arc.span.min; |
| result[i][sizes[i]++] = arc; |
| } |
| |
| return result; |
| } |
| |
| /* |
| Topological sort. |
| */ |
| private Arc[] topologicalSort(final Arc[] arcs, int start) { |
| // todo ensure the <start> vertex is added in edge cases |
| final List<Arc> result = new ArrayList<Arc>(); |
| new Object() { |
| Arc[][] arcsByFirstVertex = groupArcsByFirstVertex(arcs); |
| int[] visited = new int[getCount() + 1]; |
| |
| boolean completesCycle(int loc) { |
| int state = visited[loc]; |
| if (state == UNVISITED) { |
| visited[loc] = PENDING; |
| for (Arc arc : arcsByFirstVertex[loc]) { |
| Interval span = arc.span; |
| // the recursive call |
| if (completesCycle(span.max)) { |
| // which arcs get set here is dependent on the order |
| // in which we explore nodes |
| arc.completesCycle = true; |
| } |
| result.add(arc); |
| } |
| visited[loc] = COMPLETE; |
| } else if (state == PENDING) { |
| return true; |
| } else if (state == COMPLETE) { |
| } |
| return false; |
| } |
| }.completesCycle(start); |
| Collections.reverse(result); |
| assert arcs.length == result.size(); |
| return result.toArray(new Arc[result.size()]); |
| } |
| |
| private boolean[] findUsed(Collection<Arc> arcs) { |
| boolean[] result = new boolean[getCount()]; |
| for (Arc arc : arcs) { |
| Interval span = arc.span; |
| int min = min(span.min, span.max); |
| int max = max(span.min, span.max); |
| for (int i = min; i < max; i++) { |
| result[i] = true; |
| } |
| } |
| return result; |
| } |
| |
| // todo unify with findUsed above. Both routines analyze which rows/columns are empty. |
| private Collection<Interval> getSpacers() { |
| List<Interval> result = new ArrayList<Interval>(); |
| int N = getCount() + 1; |
| int[] leadingEdgeCount = new int[N]; |
| int[] trailingEdgeCount = new int[N]; |
| for (int i = 0, size = getChildCount(); i < size; i++) { |
| LayoutParams lp = getLayoutParams(getChildAt(i)); |
| Group g = horizontal ? lp.columnGroup : lp.rowGroup; |
| Interval span = g.span; |
| leadingEdgeCount[span.min]++; |
| trailingEdgeCount[span.max]++; |
| } |
| |
| int lastTrailingEdge = 0; |
| |
| // treat the parent's edges like peer edges of the opposite type |
| trailingEdgeCount[0] = 1; |
| leadingEdgeCount[N - 1] = 1; |
| |
| for (int i = 0; i < N; i++) { |
| if (trailingEdgeCount[i] > 0) { |
| lastTrailingEdge = i; |
| continue; // if this is also a leading edge, don't add a space of length zero |
| } |
| if (leadingEdgeCount[i] > 0) { |
| result.add(new Interval(lastTrailingEdge, i)); |
| } |
| } |
| return result; |
| } |
| |
| private Arc[] createArcs() { |
| List<Arc> spanToSize = new ArrayList<Arc>(); |
| |
| // Add all the preferred elements that were not defined by the user. |
| PackedMap<Interval, MutableInt> spanSizes = getSpanSizes(); |
| for (int i = 0; i < spanSizes.keys.length; i++) { |
| Interval key = spanSizes.keys[i]; |
| MutableInt value = spanSizes.values[i]; |
| // todo remove value duplicate |
| include2(spanToSize, key, value, value, accommodateBothMinAndMax); |
| } |
| |
| // Find redundant rows/cols and glue them together with 0-length arcs to link the tree |
| boolean[] used = findUsed(spanToSize); |
| for (int i = 0; i < getCount(); i++) { |
| if (!used[i]) { |
| Interval span = new Interval(i, i + 1); |
| include(spanToSize, span, new MutableInt(0)); |
| include(spanToSize, span.inverse(), new MutableInt(0)); |
| } |
| } |
| |
| if (mOrderPreserved) { |
| // Add preferred gaps |
| for (int i = 0; i < getCount(); i++) { |
| if (used[i]) { |
| include2(spanToSize, new Interval(i, i + 1), 0, 0, false); |
| } |
| } |
| } else { |
| for (Interval gap : getSpacers()) { |
| include2(spanToSize, gap, 0, 0, false); |
| } |
| } |
| Arc[] arcs = spanToSize.toArray(new Arc[spanToSize.size()]); |
| return topologicalSort(arcs, 0); |
| } |
| |
| public Arc[] getArcs() { |
| if (arcs == null) { |
| arcs = createArcs(); |
| } |
| if (!arcsValid) { |
| getSpanSizes(); |
| arcsValid = true; |
| } |
| return arcs; |
| } |
| |
| private boolean relax(int[] locations, Arc entry) { |
| Interval span = entry.span; |
| int u = span.min; |
| int v = span.max; |
| int value = entry.value.value; |
| int candidate = locations[u] + value; |
| if (candidate > locations[v]) { |
| locations[v] = candidate; |
| return true; |
| } |
| return false; |
| } |
| |
| /* |
| Bellman-Ford variant - modified to reduce typical running time from O(N^2) to O(N) |
| |
| GridLayout converts its requirements into a system of linear constraints of the |
| form: |
| |
| x[i] - x[j] < a[k] |
| |
| Where the x[i] are variables and the a[k] are constants. |
| |
| For example, if the variables were instead labeled x, y, z we might have: |
| |
| x - y < 17 |
| y - z < 23 |
| z - x < 42 |
| |
| This is a special case of the Linear Programming problem that is, in turn, |
| equivalent to the single-source shortest paths problem on a digraph, for |
| which the O(n^2) Bellman-Ford algorithm the most commonly used general solution. |
| |
| Other algorithms are faster in the case where no arcs have negative weights |
| but allowing negative weights turns out to be the same as accommodating maximum |
| size requirements as well as minimum ones. |
| |
| Bellman-Ford works by iteratively 'relaxing' constraints over all nodes (an O(N) |
| process) and performing this step N times. Proof of correctness hinges on the |
| fact that there can be no negative weight chains of length > N - unless a |
| 'negative weight loop' exists. The algorithm catches this case in a final |
| checking phase that reports failure. |
| |
| By topologically sorting the nodes and checking this condition at each step |
| typical layout problems complete after the first iteration and the algorithm |
| completes in O(N) steps with very low constants. |
| */ |
| private int[] solve(Arc[] arcs, int[] locations) { |
| int N = getCount() + 1; // The number of vertices is the number of columns/rows + 1. |
| |
| boolean changed = false; |
| // We take one extra pass over traditional Bellman-Ford (and omit their final step) |
| for (int i = 0; i < N; i++) { |
| changed = false; |
| for (int j = 0, length = arcs.length; j < length; j++) { |
| changed = changed | relax(locations, arcs[j]); |
| } |
| if (!changed) { |
| if (DEBUG) { |
| Log.d(TAG, "Iteration " + |
| " completed after " + (1 + i) + " steps out of " + N); |
| } |
| break; |
| } |
| } |
| if (changed) { |
| Log.d(TAG, "*** Algorithm failed to terminate ***"); |
| } |
| return locations; |
| } |
| |
| private void computeMargins(boolean leading) { |
| int[] margins = leading ? leadingMargins : trailingMargins; |
| for (int i = 0, size = getChildCount(); i < size; i++) { |
| View c = getChildAt(i); |
| LayoutParams lp = getLayoutParams(c); |
| Group g = horizontal ? lp.columnGroup : lp.rowGroup; |
| Interval span = g.span; |
| int index = leading ? span.min : span.max; |
| margins[index] = max(margins[index], getMargin(c, leading, horizontal)); |
| } |
| } |
| |
| private int[] getLeadingMargins() { |
| if (leadingMargins == null) { |
| leadingMargins = new int[getCount() + 1]; |
| } |
| if (!leadingMarginsValid) { |
| computeMargins(true); |
| leadingMarginsValid = true; |
| } |
| return leadingMargins; |
| } |
| |
| private int[] getTrailingMargins() { |
| if (trailingMargins == null) { |
| trailingMargins = new int[getCount() + 1]; |
| } |
| if (!trailingMarginsValid) { |
| computeMargins(false); |
| trailingMarginsValid = true; |
| } |
| return trailingMargins; |
| } |
| |
| private void addMargins() { |
| int[] leadingMargins = getLeadingMargins(); |
| int[] trailingMargins = getTrailingMargins(); |
| |
| int delta = 0; |
| for (int i = 0, N = getCount(); i < N; i++) { |
| int margins = leadingMargins[i] + trailingMargins[i + 1]; |
| delta += margins; |
| minima[i + 1] += delta; |
| } |
| } |
| |
| private int getLocationIncludingMargin(View view, boolean leading, int index) { |
| int location = locations[index]; |
| int margin; |
| if (!mMarginsIncludedInAlignment) { |
| margin = (leading ? leadingMargins : trailingMargins)[index]; |
| } else { |
| margin = getMargin(view, leading, horizontal); |
| } |
| return leading ? (location + margin) : (location - margin); |
| } |
| |
| private void computeMinima(int[] a) { |
| Arrays.fill(a, MIN_VALUE); |
| a[0] = 0; |
| solve(getArcs(), a); |
| if (!mMarginsIncludedInAlignment) { |
| addMargins(); |
| } |
| } |
| |
| private int[] getMinima() { |
| if (minima == null) { |
| int N = getCount() + 1; |
| minima = new int[N]; |
| } |
| if (!minimaValid) { |
| computeMinima(minima); |
| minimaValid = true; |
| } |
| return minima; |
| } |
| |
| private void computeWeights() { |
| for (int i = 0, N = getChildCount(); i < N; i++) { |
| LayoutParams lp = getLayoutParams(getChildAt(i)); |
| Group g = horizontal ? lp.columnGroup : lp.rowGroup; |
| Interval span = g.span; |
| int penultimateIndex = span.max - 1; |
| weights[penultimateIndex] += horizontal ? lp.columnWeight : lp.rowWeight; |
| } |
| } |
| |
| private float[] getWeights() { |
| if (weights == null) { |
| int N = getCount() + 1; |
| weights = new float[N]; |
| } |
| computeWeights(); |
| return weights; |
| } |
| |
| private int[] getLocations() { |
| if (locations == null) { |
| int N = getCount() + 1; |
| locations = new int[N]; |
| } |
| return locations; |
| } |
| |
| // External entry points |
| |
| private int size(int[] locations) { |
| return locations[locations.length - 1] - locations[0]; |
| } |
| |
| private int getMin() { |
| return size(getMinima()); |
| } |
| |
| private void layout(int targetSize) { |
| int[] mins = getMinima(); |
| |
| int totalDelta = max(0, targetSize - size(mins)); // confine to expansion |
| |
| float[] weights = getWeights(); |
| float totalWeight = sum(weights); |
| |
| if (totalWeight == 0f) { |
| weights[weights.length - 1] = 1; |
| totalWeight = 1; |
| } |
| |
| int[] locations = getLocations(); |
| int cumulativeDelta = 0; |
| |
| for (int i = 0; i < locations.length; i++) { |
| float weight = weights[i]; |
| int delta = (int) (totalDelta * weight / totalWeight); |
| cumulativeDelta += delta; |
| locations[i] = mins[i] + cumulativeDelta; |
| |
| totalDelta -= delta; |
| totalWeight -= weight; |
| } |
| } |
| |
| private void invalidateStructure() { |
| countValid = false; |
| |
| groupBounds = null; |
| spanSizes = null; |
| leadingMargins = null; |
| trailingMargins = null; |
| minima = null; |
| weights = null; |
| locations = null; |
| |
| invalidateValues(); |
| } |
| |
| private void invalidateValues() { |
| groupBoundsValid = false; |
| spanSizesValid = false; |
| arcsValid = false; |
| leadingMarginsValid = false; |
| trailingMarginsValid = false; |
| minimaValid = false; |
| } |
| } |
| |
| /** |
| * Layout information associated with each of the children of a GridLayout. |
| * <p> |
| * GridLayout supports both row and column spanning and arbitrary forms of alignment within |
| * each cell group. The fundamental parameters associated with each cell group are |
| * gathered into their vertical and horizontal components and stored |
| * in the {@link #rowGroup} and {@link #columnGroup} layout parameters. |
| * {@link Group Groups} are immutable structures and may be shared between the layout |
| * parameters of different children. |
| * <p> |
| * The row and column groups contain the leading and trailing indices along each axis |
| * and together specify the four grid indices that delimit the cells of this cell group. |
| * <p> |
| * The {@link Group#alignment alignment} fields of the row and column groups together specify |
| * both aspects of alignment within the cell group. It is also possible to specify a child's |
| * alignment within its cell group by using the {@link GridLayout.LayoutParams#setGravity(int)} |
| * method. |
| * <p> |
| * See {@link GridLayout} for a description of the conventions used by GridLayout |
| * in reference to grid indices. |
| * |
| * <h4>Default values</h4> |
| * |
| * <ul> |
| * <li>{@link #width} = {@link #WRAP_CONTENT}</li> |
| * <li>{@link #height} = {@link #WRAP_CONTENT}</li> |
| * <li>{@link #topMargin} = 0 when |
| * {@link GridLayout#setUseDefaultMargins(boolean) useDefaultMargins} is |
| * <code>false</code>; otherwise {@link #UNDEFINED}, to |
| * indicate that a default value should be computed on demand. </li> |
| * <li>{@link #leftMargin} = 0 when |
| * {@link GridLayout#setUseDefaultMargins(boolean) useDefaultMargins} is |
| * <code>false</code>; otherwise {@link #UNDEFINED}, to |
| * indicate that a default value should be computed on demand. </li> |
| * <li>{@link #bottomMargin} = 0 when |
| * {@link GridLayout#setUseDefaultMargins(boolean) useDefaultMargins} is |
| * <code>false</code>; otherwise {@link #UNDEFINED}, to |
| * indicate that a default value should be computed on demand. </li> |
| * <li>{@link #rightMargin} = 0 when |
| * {@link GridLayout#setUseDefaultMargins(boolean) useDefaultMargins} is |
| * <code>false</code>; otherwise {@link #UNDEFINED}, to |
| * indicate that a default value should be computed on demand. </li> |
| * <li>{@link #rowGroup}<code>.span</code> = <code>[0, 1]</code> </li> |
| * <li>{@link #rowGroup}<code>.alignment</code> = {@link #BASELINE} </li> |
| * <li>{@link #columnGroup}<code>.span</code> = <code>[0, 1]</code> </li> |
| * <li>{@link #columnGroup}<code>.alignment</code> = {@link #LEFT} </li> |
| * <li>{@link #rowWeight} = <code>0f</code> </li> |
| * <li>{@link #columnWeight} = <code>0f</code> </li> |
| * </ul> |
| * |
| * @attr ref android.R.styleable#GridLayout_Layout_layout_row |
| * @attr ref android.R.styleable#GridLayout_Layout_layout_rowSpan |
| * @attr ref android.R.styleable#GridLayout_Layout_layout_rowWeight |
| * @attr ref android.R.styleable#GridLayout_Layout_layout_column |
| * @attr ref android.R.styleable#GridLayout_Layout_layout_columnSpan |
| * @attr ref android.R.styleable#GridLayout_Layout_layout_columnWeight |
| * @attr ref android.R.styleable#GridLayout_Layout_layout_gravity |
| */ |
| public static class LayoutParams extends MarginLayoutParams { |
| |
| // Default values |
| |
| private static final int DEFAULT_WIDTH = WRAP_CONTENT; |
| private static final int DEFAULT_HEIGHT = WRAP_CONTENT; |
| private static final int DEFAULT_MARGIN = UNDEFINED; |
| private static final int DEFAULT_ROW = UNDEFINED; |
| private static final int DEFAULT_COLUMN = UNDEFINED; |
| private static final Interval DEFAULT_SPAN = new Interval(0, 1); |
| private static final int DEFAULT_SPAN_SIZE = DEFAULT_SPAN.size(); |
| private static final Alignment DEFAULT_HORIZONTAL_ALIGNMENT = LEFT; |
| private static final Alignment DEFAULT_VERTCIAL_ALGIGNMENT = BASELINE; |
| private static final Group DEFAULT_HORIZONTAL_GROUP = |
| new Group(DEFAULT_SPAN, DEFAULT_HORIZONTAL_ALIGNMENT); |
| private static final Group DEFAULT_VERTICAL_GROUP = |
| new Group(DEFAULT_SPAN, DEFAULT_VERTCIAL_ALGIGNMENT); |
| private static final int DEFAULT_WEIGHT_0 = 0; |
| private static final int DEFAULT_WEIGHT_1 = 1; |
| |
| // Misc |
| |
| private static final Rect CONTAINER_BOUNDS = new Rect(0, 0, 2, 2); |
| private static final Alignment[] HORIZONTAL_ALIGNMENTS = { LEFT, CENTER, RIGHT }; |
| private static final Alignment[] VERTICAL_ALIGNMENTS = { TOP, CENTER, BOTTOM }; |
| |
| // TypedArray indices |
| |
| private static final int MARGIN = styleable.ViewGroup_MarginLayout_layout_margin; |
| private static final int LEFT_MARGIN = styleable.ViewGroup_MarginLayout_layout_marginLeft; |
| private static final int TOP_MARGIN = styleable.ViewGroup_MarginLayout_layout_marginTop; |
| private static final int RIGHT_MARGIN = styleable.ViewGroup_MarginLayout_layout_marginRight; |
| private static final int BOTTOM_MARGIN = |
| styleable.ViewGroup_MarginLayout_layout_marginBottom; |
| |
| private static final int COLUMN = styleable.GridLayout_Layout_layout_column; |
| private static final int COLUMN_SPAN = styleable.GridLayout_Layout_layout_columnSpan; |
| private static final int COLUMN_WEIGHT = styleable.GridLayout_Layout_layout_columnWeight; |
| private static final int ROW = styleable.GridLayout_Layout_layout_row; |
| private static final int ROW_SPAN = styleable.GridLayout_Layout_layout_rowSpan; |
| private static final int ROW_WEIGHT = styleable.GridLayout_Layout_layout_rowWeight; |
| private static final int GRAVITY = styleable.GridLayout_Layout_layout_gravity; |
| |
| // Instance variables |
| |
| /** |
| * The group that specifies the vertical characteristics of the cell group |
| * described by these layout parameters. |
| */ |
| public Group rowGroup; |
| /** |
| * The group that specifies the horizontal characteristics of the cell group |
| * described by these layout parameters. |
| */ |
| public Group columnGroup; |
| /** |
| * The proportional space that should be taken by the associated row group |
| * during excess space distribution. |
| */ |
| public float rowWeight; |
| /** |
| * The proportional space that should be taken by the associated column group |
| * during excess space distribution. |
| */ |
| public float columnWeight; |
| |
| // Constructors |
| |
| private LayoutParams( |
| int width, int height, |
| int left, int top, int right, int bottom, |
| Group rowGroup, Group columnGroup, float rowWeight, float columnWeight) { |
| super(width, height); |
| setMargins(left, top, right, bottom); |
| this.rowGroup = rowGroup; |
| this.columnGroup = columnGroup; |
| this.rowWeight = rowWeight; |
| this.columnWeight = columnWeight; |
| } |
| |
| /** |
| * Constructs a new LayoutParams instance for this <code>rowGroup</code> |
| * and <code>columnGroup</code>. All other fields are initialized with |
| * default values as defined in {@link LayoutParams}. |
| * |
| * @param rowGroup the rowGroup |
| * @param columnGroup the columnGroup |
| */ |
| public LayoutParams(Group rowGroup, Group columnGroup) { |
| this(DEFAULT_WIDTH, DEFAULT_HEIGHT, |
| DEFAULT_MARGIN, DEFAULT_MARGIN, DEFAULT_MARGIN, DEFAULT_MARGIN, |
| rowGroup, columnGroup, DEFAULT_WEIGHT_0, DEFAULT_WEIGHT_0); |
| } |
| |
| /** |
| * Constructs a new LayoutParams with default values as defined in {@link LayoutParams}. |
| */ |
| public LayoutParams() { |
| this(DEFAULT_HORIZONTAL_GROUP, DEFAULT_VERTICAL_GROUP); |
| } |
| |
| // Copying constructors |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public LayoutParams(ViewGroup.LayoutParams params) { |
| super(params); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public LayoutParams(MarginLayoutParams params) { |
| super(params); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| public LayoutParams(LayoutParams that) { |
| super(that); |
| this.columnGroup = that.columnGroup; |
| this.rowGroup = that.rowGroup; |
| this.columnWeight = that.columnWeight; |
| this.rowWeight = that.rowWeight; |
| } |
| |
| // AttributeSet constructors |
| |
| private LayoutParams(Context context, AttributeSet attrs, int defaultGravity) { |
| super(context, attrs); |
| reInitSuper(context, attrs); |
| init(context, attrs, defaultGravity); |
| } |
| |
| /** |
| * {@inheritDoc} |
| * |
| * Values not defined in the attribute set take the default values |
| * defined in {@link LayoutParams}. |
| */ |
| public LayoutParams(Context context, AttributeSet attrs) { |
| this(context, attrs, Gravity.NO_GRAVITY); |
| } |
| |
| // Implementation |
| |
| private static boolean definesVertical(int gravity) { |
| return gravity > 0 && (gravity & Gravity.VERTICAL_GRAVITY_MASK) != 0; |
| } |
| |
| private static boolean definesHorizontal(int gravity) { |
| return gravity > 0 && (gravity & Gravity.HORIZONTAL_GRAVITY_MASK) != 0; |
| } |
| |
| private static <T> T getAlignment(T[] alignments, T fill, int min, int max, |
| boolean isUndefined, T defaultValue) { |
| if (isUndefined) { |
| return defaultValue; |
| } |
| return min != max ? fill : alignments[min]; |
| } |
| |
| // Reinitialise the margins using a different default policy than MarginLayoutParams. |
| // Here we use the value UNDEFINED (as distinct from zero) to represent the undefined state |
| // so that a layout manager default can be accessed post set up. We need this as, at the |
| // point of installation, we do not know how many rows/cols there are and therefore |
| // which elements are positioned next to the container's trailing edges. We need to |
| // know this as margins around the container's boundary should have different |
| // defaults to those between peers. |
| |
| // This method could be parametrized and moved into MarginLayout. |
| private void reInitSuper(Context context, AttributeSet attrs) { |
| TypedArray a = context.obtainStyledAttributes(attrs, styleable.ViewGroup_MarginLayout); |
| try { |
| int margin = a.getDimensionPixelSize(MARGIN, DEFAULT_MARGIN); |
| |
| this.leftMargin = a.getDimensionPixelSize(LEFT_MARGIN, margin); |
| this.topMargin = a.getDimensionPixelSize(TOP_MARGIN, margin); |
| this.rightMargin = a.getDimensionPixelSize(RIGHT_MARGIN, margin); |
| this.bottomMargin = a.getDimensionPixelSize(BOTTOM_MARGIN, margin); |
| } finally { |
| a.recycle(); |
| } |
| } |
| |
| // Gravity. For conversion from the static the integers defined in the Gravity class, |
| // use Gravity.apply() to apply gravity to a view of zero size and see where it ends up. |
| private static Alignment getHorizontalAlignment(int gravity, int width) { |
| Rect r = new Rect(0, 0, 0, 0); |
| Gravity.apply(gravity, 0, 0, CONTAINER_BOUNDS, r); |
| |
| boolean fill = width == MATCH_PARENT; |
| Alignment defaultAlignment = fill ? FILL : DEFAULT_HORIZONTAL_ALIGNMENT; |
| return getAlignment(HORIZONTAL_ALIGNMENTS, FILL, r.left, r.right, |
| !definesHorizontal(gravity), defaultAlignment); |
| } |
| |
| private static Alignment getVerticalAlignment(int gravity, int height) { |
| Rect r = new Rect(0, 0, 0, 0); |
| Gravity.apply(gravity, 0, 0, CONTAINER_BOUNDS, r); |
| |
| boolean fill = height == MATCH_PARENT; |
| Alignment defaultAlignment = fill ? FILL : DEFAULT_VERTCIAL_ALGIGNMENT; |
| return getAlignment(VERTICAL_ALIGNMENTS, FILL, r.top, r.bottom, |
| !definesVertical(gravity), defaultAlignment); |
| } |
| |
| private int getDefaultWeight(int size) { |
| return (size == MATCH_PARENT) ? DEFAULT_WEIGHT_1 : DEFAULT_WEIGHT_0; |
| } |
| |
| private void init(Context context, AttributeSet attrs, int defaultGravity) { |
| TypedArray a = context.obtainStyledAttributes(attrs, styleable.GridLayout_Layout); |
| try { |
| int gravity = a.getInteger(GRAVITY, defaultGravity); |
| |
| int column = a.getInteger(COLUMN, DEFAULT_COLUMN); |
| int columnSpan = a.getInteger(COLUMN_SPAN, DEFAULT_SPAN_SIZE); |
| Interval hSpan = new Interval(column, column + columnSpan); |
| this.columnGroup = new Group(hSpan, getHorizontalAlignment(gravity, width)); |
| this.columnWeight = a.getFloat(COLUMN_WEIGHT, getDefaultWeight(width)); |
| |
| int row = a.getInteger(ROW, DEFAULT_ROW); |
| int rowSpan = a.getInteger(ROW_SPAN, DEFAULT_SPAN_SIZE); |
| Interval vSpan = new Interval(row, row + rowSpan); |
| this.rowGroup = new Group(vSpan, getVerticalAlignment(gravity, height)); |
| this.rowWeight = a.getFloat(ROW_WEIGHT, getDefaultWeight(height)); |
| } finally { |
| a.recycle(); |
| } |
| } |
| |
| /** |
| * Describes how the child views are positioned. Default is <code>LEFT | BASELINE</code>. |
| * |
| * @param gravity the new gravity. See {@link android.view.Gravity}. |
| * |
| * @attr ref android.R.styleable#GridLayout_Layout_layout_gravity |
| */ |
| public void setGravity(int gravity) { |
| columnGroup = columnGroup.copyWriteAlignment(getHorizontalAlignment(gravity, width)); |
| rowGroup = rowGroup.copyWriteAlignment(getVerticalAlignment(gravity, height)); |
| } |
| |
| @Override |
| protected void setBaseAttributes(TypedArray attributes, int widthAttr, int heightAttr) { |
| this.width = attributes.getLayoutDimension(widthAttr, DEFAULT_WIDTH); |
| this.height = attributes.getLayoutDimension(heightAttr, DEFAULT_HEIGHT); |
| } |
| |
| private void setVerticalGroupSpan(Interval span) { |
| rowGroup = rowGroup.copyWriteSpan(span); |
| } |
| |
| private void setHorizontalGroupSpan(Interval span) { |
| columnGroup = columnGroup.copyWriteSpan(span); |
| } |
| } |
| |
| /* |
| In place of a HashMap from span to Int, use an array of key/value pairs - stored in Arcs. |
| Add the mutables completesCycle flag to avoid creating another hash table for detecting cycles. |
| */ |
| private static class Arc { |
| public final Interval span; |
| public final MutableInt value; |
| public boolean completesCycle; |
| |
| public Arc(Interval span, MutableInt value) { |
| this.span = span; |
| this.value = value; |
| } |
| |
| @Override |
| public String toString() { |
| return span + " " + (completesCycle ? "+>" : "->") + " " + value; |
| } |
| } |
| |
| // A mutable Integer - used to avoid heap allocation during the layout operation |
| |
| private static class MutableInt { |
| public int value; |
| |
| private MutableInt() { |
| reset(); |
| } |
| |
| private MutableInt(int value) { |
| this.value = value; |
| } |
| |
| private void reset() { |
| value = Integer.MIN_VALUE; |
| } |
| } |
| |
| /* |
| This data structure is used in place of a Map where we have an index that refers to the order |
| in which each key/value pairs were added to the map. In this case we store keys and values |
| in arrays of a length that is equal to the number of unique keys. We also maintain an |
| array of indexes from insertion order to the compacted arrays of keys and values. |
| |
| Note that behavior differs from that of a LinkedHashMap in that repeated entries |
| *do* get added multiples times. So the length of index is equals to the number of |
| items added. |
| |
| This is useful in the GridLayout class where we can rely on the order of children not |
| changing during layout - to use integer-based lookup for our internal structures |
| rather than using (and storing) an implementation of Map<Key, ?>. |
| */ |
| @SuppressWarnings(value = "unchecked") |
| private static class PackedMap<K, V> { |
| public final int[] index; |
| public final K[] keys; |
| public final V[] values; |
| |
| private PackedMap(K[] keys, V[] values) { |
| this.index = createIndex(keys); |
| |
| this.keys = compact(keys, index); |
| this.values = compact(values, index); |
| } |
| |
| private K getKey(int i) { |
| return keys[index[i]]; |
| } |
| |
| private V getValue(int i) { |
| return values[index[i]]; |
| } |
| |
| private static <K> int[] createIndex(K[] keys) { |
| int size = keys.length; |
| int[] result = new int[size]; |
| |
| Map<K, Integer> keyToIndex = new HashMap<K, Integer>(); |
| for (int i = 0; i < size; i++) { |
| K key = keys[i]; |
| Integer index = keyToIndex.get(key); |
| if (index == null) { |
| index = keyToIndex.size(); |
| keyToIndex.put(key, index); |
| } |
| result[i] = index; |
| } |
| return result; |
| } |
| |
| private static int max(int[] a, int valueIfEmpty) { |
| int result = valueIfEmpty; |
| for (int i = 0, length = a.length; i < length; i++) { |
| result = Math.max(result, a[i]); |
| } |
| return result; |
| } |
| |
| /* |
| Create a compact array of keys or values using the supplied index. |
| */ |
| private static <K> K[] compact(K[] a, int[] index) { |
| int size = a.length; |
| Class<?> componentType = a.getClass().getComponentType(); |
| K[] result = (K[]) Array.newInstance(componentType, max(index, -1) + 1); |
| |
| // this overwrite duplicates, retaining the last equivalent entry |
| for (int i = 0; i < size; i++) { |
| result[index[i]] = a[i]; |
| } |
| return result; |
| } |
| } |
| |
| /* |
| For each Group (with a given alignment) we need to store the amount of space required |
| above the alignment point and the amount of space required below it. One side of this |
| calculation is always 0 for LEADING and TRAILING alignments but we don't make use of this. |
| For CENTER and BASELINE alignments both sides are needed and in the BASELINE case no |
| simple optimisations are possible. |
| |
| The general algorithm therefore is to create a Map (actually a PackedMap) from |
| Group to Bounds and to loop through all Views in the group taking the maximum |
| of the values for each View. |
| */ |
| private static class Bounds { |
| public int below; |
| public int above; |
| |
| private Bounds(int below, int above) { |
| this.below = below; |
| this.above = above; |
| } |
| |
| private Bounds() { |
| reset(); |
| } |
| |
| private void reset() { |
| below = Integer.MAX_VALUE; |
| above = Integer.MIN_VALUE; |
| } |
| |
| private void include(int below, int above) { |
| this.below = min(this.below, below); |
| this.above = max(this.above, above); |
| } |
| |
| private int size() { |
| return above - below; |
| } |
| |
| @Override |
| public String toString() { |
| return "Bounds{" + |
| "below=" + below + |
| ", above=" + above + |
| '}'; |
| } |
| } |
| |
| /** |
| * An Interval represents a contiguous range of values that lie between |
| * the interval's {@link #min} and {@link #max} values. |
| * <p> |
| * Intervals are immutable so may be passed as values and used as keys in hash tables. |
| * It is not necessary to have multiple instances of Intervals which have the same |
| * {@link #min} and {@link #max} values. |
| * <p> |
| * Intervals are often written as <code>[min, max]</code> and represent the set of values |
| * <em>x</em> such that <em>min <= x < max</em>. |
| */ |
| /* package */ static class Interval { |
| /** |
| * The minimum value. |
| */ |
| public final int min; |
| |
| /** |
| * The maximum value. |
| */ |
| public final int max; |
| |
| /** |
| * Construct a new Interval, <code>interval</code>, where: |
| * <ul> |
| * <li> <code>interval.min = min</code> </li> |
| * <li> <code>interval.max = max</code> </li> |
| * </ul> |
| * |
| * @param min the minimum value. |
| * @param max the maximum value. |
| */ |
| public Interval(int min, int max) { |
| this.min = min; |
| this.max = max; |
| } |
| |
| private int size() { |
| return max - min; |
| } |
| |
| private Interval inverse() { |
| return new Interval(max, min); |
| } |
| |
| /** |
| * Returns true if the {@link #getClass class}, {@link #min} and {@link #max} properties |
| * of this Interval and the supplied parameter are pairwise equal; false otherwise. |
| * |
| * @param that the object to compare this interval with. |
| * |
| * @return {@code true} if the specified object is equal to this |
| * {@code Interval}; {@code false} otherwise. |
| */ |
| @Override |
| public boolean equals(Object that) { |
| if (this == that) { |
| return true; |
| } |
| if (that == null || getClass() != that.getClass()) { |
| return false; |
| } |
| |
| Interval interval = (Interval) that; |
| |
| if (max != interval.max) { |
| return false; |
| } |
| if (min != interval.min) { |
| return false; |
| } |
| |
| return true; |
| } |
| |
| @Override |
| public int hashCode() { |
| int result = min; |
| result = 31 * result + max; |
| return result; |
| } |
| |
| @Override |
| public String toString() { |
| return "[" + min + ", " + max + "]"; |
| } |
| } |
| |
| /** |
| * A group specifies either the horizontal or vertical characteristics of a group of |
| * cells. |
| * <p> |
| * Groups are immutable and so may be shared between views with the same |
| * <code>span</code> and <code>alignment</code>. |
| */ |
| public static class Group { |
| /** |
| * The grid indices of the leading and trailing edges of this cell group for the |
| * appropriate axis. |
| * <p> |
| * See {@link GridLayout} for a description of the conventions used by GridLayout |
| * for grid indices. |
| */ |
| /* package */ final Interval span; |
| /** |
| * Specifies how cells should be aligned in this group. |
| * For row groups, this specifies the vertical alignment. |
| * For column groups, this specifies the horizontal alignment. |
| */ |
| public final Alignment alignment; |
| |
| /** |
| * Construct a new Group, <code>group</code>, where: |
| * <ul> |
| * <li> <code>group.span = span</code> </li> |
| * <li> <code>group.alignment = alignment</code> </li> |
| * </ul> |
| * |
| * @param span the span. |
| * @param alignment the alignment. |
| */ |
| /* package */ Group(Interval span, Alignment alignment) { |
| this.span = span; |
| this.alignment = alignment; |
| } |
| |
| /** |
| * Construct a new Group, <code>group</code>, where: |
| * <ul> |
| * <li> <code>group.span = [min, max]</code> </li> |
| * <li> <code>group.alignment = alignment</code> </li> |
| * </ul> |
| * |
| * @param min the minimum. |
| * @param max the maximum. |
| * @param alignment the alignment. |
| */ |
| public Group(int min, int max, Alignment alignment) { |
| this(new Interval(min, max), alignment); |
| } |
| |
| /** |
| * Construct a new Group, <code>group</code>, where: |
| * <ul> |
| * <li> <code>group.span = [min, min + 1]</code> </li> |
| * <li> <code>group.alignment = alignment</code> </li> |
| * </ul> |
| * |
| * @param min the minimum. |
| * @param alignment the alignment. |
| */ |
| public Group(int min, Alignment alignment) { |
| this(min, min + 1, alignment); |
| } |
| |
| private Group copyWriteSpan(Interval span) { |
| return new Group(span, alignment); |
| } |
| |
| private Group copyWriteAlignment(Alignment alignment) { |
| return new Group(span, alignment); |
| } |
| |
| /** |
| * Returns true if the {@link #getClass class}, {@link #alignment} and <code>span</code> |
| * properties of this Group and the supplied parameter are pairwise equal; false otherwise. |
| * |
| * @param that the object to compare this group with. |
| * |
| * @return {@code true} if the specified object is equal to this |
| * {@code Group}; {@code false} otherwise. |
| */ |
| @Override |
| public boolean equals(Object that) { |
| if (this == that) { |
| return true; |
| } |
| if (that == null || getClass() != that.getClass()) { |
| return false; |
| } |
| |
| Group group = (Group) that; |
| |
| if (!alignment.equals(group.alignment)) { |
| return false; |
| } |
| if (!span.equals(group.span)) { |
| return false; |
| } |
| |
| return true; |
| } |
| |
| @Override |
| public int hashCode() { |
| int result = span.hashCode(); |
| result = 31 * result + alignment.hashCode(); |
| return result; |
| } |
| } |
| |
| /** |
| * Alignments specify where a view should be placed within a cell group and |
| * what size it should be. |
| * <p> |
| * The {@link LayoutParams} class contains a {@link LayoutParams#rowGroup rowGroup} |
| * and a {@link LayoutParams#columnGroup columnGroup} each of which contains an |
| * {@link Group#alignment alignment}. Overall placement of the view in the cell |
| * group is specified by the two alignments which act along each axis independently. |
| * <p> |
| * An Alignment implementation must define the {@link #getAlignmentValue(View, int)} |
| * to return the appropriate value for the type of alignment being defined. |
| * The enclosing algorithms position the children |
| * so that the values returned from the alignment |
| * are the same for all of the views in a group. |
| * <p> |
| * The GridLayout class defines the most common alignments used in general layout: |
| * {@link #TOP}, {@link #LEFT}, {@link #BOTTOM}, {@link #RIGHT}, {@link #CENTER}, {@link |
| * #BASELINE} and {@link #FILL}. |
| */ |
| public static interface Alignment { |
| /** |
| * Returns an alignment value. In the case of vertical alignments the value |
| * returned should indicate the distance from the top of the view to the |
| * alignment location. |
| * For horizontal alignments measurement is made from the left edge of the component. |
| * |
| * @param view the view to which this alignment should be applied. |
| * @param viewSize the measured size of the view. |
| * @return the alignment value. |
| */ |
| public int getAlignmentValue(View view, int viewSize); |
| |
| /** |
| * Returns the size of the view specified by this alignment. |
| * In the case of vertical alignments this method should return a height; for |
| * horizontal alignments this method should return the width. |
| * |
| * @param view the view to which this alignment should be applied. |
| * @param viewSize the measured size of the view. |
| * @param cellSize the size of the cell into which this view will be placed. |
| * @return the aligned size. |
| */ |
| public int getSizeInCell(View view, int viewSize, int cellSize); |
| } |
| |
| private static abstract class AbstractAlignment implements Alignment { |
| public int getSizeInCell(View view, int viewSize, int cellSize) { |
| return viewSize; |
| } |
| } |
| |
| private static final Alignment LEADING = new AbstractAlignment() { |
| public int getAlignmentValue(View view, int viewSize) { |
| return 0; |
| } |
| |
| }; |
| |
| private static final Alignment TRAILING = new AbstractAlignment() { |
| public int getAlignmentValue(View view, int viewSize) { |
| return viewSize; |
| } |
| }; |
| |
| /** |
| * Indicates that a view should be aligned with the <em>top</em> |
| * edges of the other views in its cell group. |
| */ |
| public static final Alignment TOP = LEADING; |
| |
| /** |
| * Indicates that a view should be aligned with the <em>bottom</em> |
| * edges of the other views in its cell group. |
| */ |
| public static final Alignment BOTTOM = TRAILING; |
| |
| /** |
| * Indicates that a view should be aligned with the <em>right</em> |
| * edges of the other views in its cell group. |
| */ |
| public static final Alignment RIGHT = TRAILING; |
| |
| /** |
| * Indicates that a view should be aligned with the <em>left</em> |
| * edges of the other views in its cell group. |
| */ |
| public static final Alignment LEFT = LEADING; |
| |
| /** |
| * Indicates that a view should be <em>centered</em> with the other views in its cell group. |
| * This constant may be used in both {@link LayoutParams#rowGroup rowGroups} and {@link |
| * LayoutParams#columnGroup columnGroups}. |
| */ |
| public static final Alignment CENTER = new AbstractAlignment() { |
| public int getAlignmentValue(View view, int viewSize) { |
| return viewSize >> 1; |
| } |
| }; |
| |
| /** |
| * Indicates that a view should be aligned with the <em>baselines</em> |
| * of the other views in its cell group. |
| * This constant may only be used as an alignment in {@link LayoutParams#rowGroup rowGroups}. |
| * |
| * @see View#getBaseline() |
| */ |
| public static final Alignment BASELINE = new AbstractAlignment() { |
| public int getAlignmentValue(View view, int viewSize) { |
| if (view == null) { |
| return UNDEFINED; |
| } |
| // todo do we need to call measure first? |
| int baseline = view.getBaseline(); |
| return baseline == -1 ? UNDEFINED : baseline; |
| } |
| |
| }; |
| |
| /** |
| * Indicates that a view should expanded to fit the boundaries of its cell group. |
| * This constant may be used in both {@link LayoutParams#rowGroup rowGroups} and |
| * {@link LayoutParams#columnGroup columnGroups}. |
| */ |
| public static final Alignment FILL = new Alignment() { |
| public int getAlignmentValue(View view, int viewSize) { |
| return UNDEFINED; |
| } |
| |
| public int getSizeInCell(View view, int viewSize, int cellSize) { |
| return cellSize; |
| } |
| }; |
| } |