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/*
* Copyright (C) 2006 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 java.util.ArrayList;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.Region;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.view.Gravity;
import android.view.View;
import android.view.ViewDebug;
import android.view.ViewGroup;
import android.view.accessibility.AccessibilityEvent;
import android.view.accessibility.AccessibilityNodeInfo;
import android.widget.RemoteViews.RemoteView;
/**
* FrameLayout is designed to block out an area on the screen to display
* a single item. Generally, FrameLayout should be used to hold a single child view, because it can
* be difficult to organize child views in a way that's scalable to different screen sizes without
* the children overlapping each other. You can, however, add multiple children to a FrameLayout
* and control their position within the FrameLayout by assigning gravity to each child, using the
* <a href="FrameLayout.LayoutParams.html#attr_android:layout_gravity">{@code
* android:layout_gravity}</a> attribute.
* <p>Child views are drawn in a stack, with the most recently added child on top.
* The size of the FrameLayout is the size of its largest child (plus padding), visible
* or not (if the FrameLayout's parent permits). Views that are {@link android.view.View#GONE} are
* used for sizing
* only if {@link #setMeasureAllChildren(boolean) setConsiderGoneChildrenWhenMeasuring()}
* is set to true.
*
* @attr ref android.R.styleable#FrameLayout_foreground
* @attr ref android.R.styleable#FrameLayout_foregroundGravity
* @attr ref android.R.styleable#FrameLayout_measureAllChildren
*/
@RemoteView
public class FrameLayout extends ViewGroup {
private static final int DEFAULT_CHILD_GRAVITY = Gravity.TOP | Gravity.START;
@ViewDebug.ExportedProperty(category = "measurement")
boolean mMeasureAllChildren = false;
@ViewDebug.ExportedProperty(category = "drawing")
private Drawable mForeground;
@ViewDebug.ExportedProperty(category = "padding")
private int mForegroundPaddingLeft = 0;
@ViewDebug.ExportedProperty(category = "padding")
private int mForegroundPaddingTop = 0;
@ViewDebug.ExportedProperty(category = "padding")
private int mForegroundPaddingRight = 0;
@ViewDebug.ExportedProperty(category = "padding")
private int mForegroundPaddingBottom = 0;
private final Rect mSelfBounds = new Rect();
private final Rect mOverlayBounds = new Rect();
@ViewDebug.ExportedProperty(category = "drawing")
private int mForegroundGravity = Gravity.FILL;
/** {@hide} */
@ViewDebug.ExportedProperty(category = "drawing")
protected boolean mForegroundInPadding = true;
boolean mForegroundBoundsChanged = false;
private final ArrayList<View> mMatchParentChildren = new ArrayList<View>(1);
public FrameLayout(Context context) {
super(context);
}
public FrameLayout(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public FrameLayout(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
TypedArray a = context.obtainStyledAttributes(attrs, com.android.internal.R.styleable.FrameLayout,
defStyle, 0);
mForegroundGravity = a.getInt(
com.android.internal.R.styleable.FrameLayout_foregroundGravity, mForegroundGravity);
final Drawable d = a.getDrawable(com.android.internal.R.styleable.FrameLayout_foreground);
if (d != null) {
setForeground(d);
}
if (a.getBoolean(com.android.internal.R.styleable.FrameLayout_measureAllChildren, false)) {
setMeasureAllChildren(true);
}
mForegroundInPadding = a.getBoolean(
com.android.internal.R.styleable.FrameLayout_foregroundInsidePadding, true);
a.recycle();
}
/**
* Describes how the foreground is positioned.
*
* @return foreground gravity.
*
* @see #setForegroundGravity(int)
*
* @attr ref android.R.styleable#FrameLayout_foregroundGravity
*/
public int getForegroundGravity() {
return mForegroundGravity;
}
/**
* Describes how the foreground is positioned. Defaults to START and TOP.
*
* @param foregroundGravity See {@link android.view.Gravity}
*
* @see #getForegroundGravity()
*
* @attr ref android.R.styleable#FrameLayout_foregroundGravity
*/
@android.view.RemotableViewMethod
public void setForegroundGravity(int foregroundGravity) {
if (mForegroundGravity != foregroundGravity) {
if ((foregroundGravity & Gravity.RELATIVE_HORIZONTAL_GRAVITY_MASK) == 0) {
foregroundGravity |= Gravity.START;
}
if ((foregroundGravity & Gravity.VERTICAL_GRAVITY_MASK) == 0) {
foregroundGravity |= Gravity.TOP;
}
mForegroundGravity = foregroundGravity;
if (mForegroundGravity == Gravity.FILL && mForeground != null) {
Rect padding = new Rect();
if (mForeground.getPadding(padding)) {
mForegroundPaddingLeft = padding.left;
mForegroundPaddingTop = padding.top;
mForegroundPaddingRight = padding.right;
mForegroundPaddingBottom = padding.bottom;
}
} else {
mForegroundPaddingLeft = 0;
mForegroundPaddingTop = 0;
mForegroundPaddingRight = 0;
mForegroundPaddingBottom = 0;
}
requestLayout();
}
}
/**
* {@inheritDoc}
*/
@Override
protected boolean verifyDrawable(Drawable who) {
return super.verifyDrawable(who) || (who == mForeground);
}
@Override
public void jumpDrawablesToCurrentState() {
super.jumpDrawablesToCurrentState();
if (mForeground != null) mForeground.jumpToCurrentState();
}
/**
* {@inheritDoc}
*/
@Override
protected void drawableStateChanged() {
super.drawableStateChanged();
if (mForeground != null && mForeground.isStateful()) {
mForeground.setState(getDrawableState());
}
}
/**
* Returns a set of layout parameters with a width of
* {@link android.view.ViewGroup.LayoutParams#MATCH_PARENT},
* and a height of {@link android.view.ViewGroup.LayoutParams#MATCH_PARENT}.
*/
@Override
protected LayoutParams generateDefaultLayoutParams() {
return new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
}
/**
* Supply a Drawable that is to be rendered on top of all of the child
* views in the frame layout. Any padding in the Drawable will be taken
* into account by ensuring that the children are inset to be placed
* inside of the padding area.
*
* @param drawable The Drawable to be drawn on top of the children.
*
* @attr ref android.R.styleable#FrameLayout_foreground
*/
public void setForeground(Drawable drawable) {
if (mForeground != drawable) {
if (mForeground != null) {
mForeground.setCallback(null);
unscheduleDrawable(mForeground);
}
mForeground = drawable;
mForegroundPaddingLeft = 0;
mForegroundPaddingTop = 0;
mForegroundPaddingRight = 0;
mForegroundPaddingBottom = 0;
if (drawable != null) {
setWillNotDraw(false);
drawable.setCallback(this);
if (drawable.isStateful()) {
drawable.setState(getDrawableState());
}
if (mForegroundGravity == Gravity.FILL) {
Rect padding = new Rect();
if (drawable.getPadding(padding)) {
mForegroundPaddingLeft = padding.left;
mForegroundPaddingTop = padding.top;
mForegroundPaddingRight = padding.right;
mForegroundPaddingBottom = padding.bottom;
}
}
} else {
setWillNotDraw(true);
}
requestLayout();
invalidate();
}
}
/**
* Returns the drawable used as the foreground of this FrameLayout. The
* foreground drawable, if non-null, is always drawn on top of the children.
*
* @return A Drawable or null if no foreground was set.
*/
public Drawable getForeground() {
return mForeground;
}
private int getPaddingLeftWithForeground() {
return mForegroundInPadding ? Math.max(mPaddingLeft, mForegroundPaddingLeft) :
mPaddingLeft + mForegroundPaddingLeft;
}
private int getPaddingRightWithForeground() {
return mForegroundInPadding ? Math.max(mPaddingRight, mForegroundPaddingRight) :
mPaddingRight + mForegroundPaddingRight;
}
private int getPaddingTopWithForeground() {
return mForegroundInPadding ? Math.max(mPaddingTop, mForegroundPaddingTop) :
mPaddingTop + mForegroundPaddingTop;
}
private int getPaddingBottomWithForeground() {
return mForegroundInPadding ? Math.max(mPaddingBottom, mForegroundPaddingBottom) :
mPaddingBottom + mForegroundPaddingBottom;
}
/**
* {@inheritDoc}
*/
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int count = getChildCount();
final boolean measureMatchParentChildren =
MeasureSpec.getMode(widthMeasureSpec) != MeasureSpec.EXACTLY ||
MeasureSpec.getMode(heightMeasureSpec) != MeasureSpec.EXACTLY;
mMatchParentChildren.clear();
int maxHeight = 0;
int maxWidth = 0;
int childState = 0;
for (int i = 0; i < count; i++) {
final View child = getChildAt(i);
if (mMeasureAllChildren || child.getVisibility() != GONE) {
measureChildWithMargins(child, widthMeasureSpec, 0, heightMeasureSpec, 0);
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
maxWidth = Math.max(maxWidth,
child.getMeasuredWidth() + lp.leftMargin + lp.rightMargin);
maxHeight = Math.max(maxHeight,
child.getMeasuredHeight() + lp.topMargin + lp.bottomMargin);
childState = combineMeasuredStates(childState, child.getMeasuredState());
if (measureMatchParentChildren) {
if (lp.width == LayoutParams.MATCH_PARENT ||
lp.height == LayoutParams.MATCH_PARENT) {
mMatchParentChildren.add(child);
}
}
}
}
// Account for padding too
maxWidth += getPaddingLeftWithForeground() + getPaddingRightWithForeground();
maxHeight += getPaddingTopWithForeground() + getPaddingBottomWithForeground();
// Check against our minimum height and width
maxHeight = Math.max(maxHeight, getSuggestedMinimumHeight());
maxWidth = Math.max(maxWidth, getSuggestedMinimumWidth());
// Check against our foreground's minimum height and width
final Drawable drawable = getForeground();
if (drawable != null) {
maxHeight = Math.max(maxHeight, drawable.getMinimumHeight());
maxWidth = Math.max(maxWidth, drawable.getMinimumWidth());
}
setMeasuredDimension(resolveSizeAndState(maxWidth, widthMeasureSpec, childState),
resolveSizeAndState(maxHeight, heightMeasureSpec,
childState << MEASURED_HEIGHT_STATE_SHIFT));
count = mMatchParentChildren.size();
if (count > 1) {
for (int i = 0; i < count; i++) {
final View child = mMatchParentChildren.get(i);
final MarginLayoutParams lp = (MarginLayoutParams) child.getLayoutParams();
int childWidthMeasureSpec;
int childHeightMeasureSpec;
if (lp.width == LayoutParams.MATCH_PARENT) {
childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(getMeasuredWidth() -
getPaddingLeftWithForeground() - getPaddingRightWithForeground() -
lp.leftMargin - lp.rightMargin,
MeasureSpec.EXACTLY);
} else {
childWidthMeasureSpec = getChildMeasureSpec(widthMeasureSpec,
getPaddingLeftWithForeground() + getPaddingRightWithForeground() +
lp.leftMargin + lp.rightMargin,
lp.width);
}
if (lp.height == LayoutParams.MATCH_PARENT) {
childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(getMeasuredHeight() -
getPaddingTopWithForeground() - getPaddingBottomWithForeground() -
lp.topMargin - lp.bottomMargin,
MeasureSpec.EXACTLY);
} else {
childHeightMeasureSpec = getChildMeasureSpec(heightMeasureSpec,
getPaddingTopWithForeground() + getPaddingBottomWithForeground() +
lp.topMargin + lp.bottomMargin,
lp.height);
}
child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
}
}
}
/**
* {@inheritDoc}
*/
@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
final int count = getChildCount();
final int parentLeft = getPaddingLeftWithForeground();
final int parentRight = right - left - getPaddingRightWithForeground();
final int parentTop = getPaddingTopWithForeground();
final int parentBottom = bottom - top - getPaddingBottomWithForeground();
mForegroundBoundsChanged = true;
for (int i = 0; i < count; i++) {
final View child = getChildAt(i);
if (child.getVisibility() != GONE) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
final int width = child.getMeasuredWidth();
final int height = child.getMeasuredHeight();
int childLeft;
int childTop;
int gravity = lp.gravity;
if (gravity == -1) {
gravity = DEFAULT_CHILD_GRAVITY;
}
final int layoutDirection = getLayoutDirection();
final int absoluteGravity = Gravity.getAbsoluteGravity(gravity, layoutDirection);
final int verticalGravity = gravity & Gravity.VERTICAL_GRAVITY_MASK;
switch (absoluteGravity & Gravity.HORIZONTAL_GRAVITY_MASK) {
case Gravity.LEFT:
childLeft = parentLeft + lp.leftMargin;
break;
case Gravity.CENTER_HORIZONTAL:
childLeft = parentLeft + (parentRight - parentLeft - width) / 2 +
lp.leftMargin - lp.rightMargin;
break;
case Gravity.RIGHT:
childLeft = parentRight - width - lp.rightMargin;
break;
default:
childLeft = parentLeft + lp.leftMargin;
}
switch (verticalGravity) {
case Gravity.TOP:
childTop = parentTop + lp.topMargin;
break;
case Gravity.CENTER_VERTICAL:
childTop = parentTop + (parentBottom - parentTop - height) / 2 +
lp.topMargin - lp.bottomMargin;
break;
case Gravity.BOTTOM:
childTop = parentBottom - height - lp.bottomMargin;
break;
default:
childTop = parentTop + lp.topMargin;
}
child.layout(childLeft, childTop, childLeft + width, childTop + height);
}
}
}
/**
* {@inheritDoc}
*/
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mForegroundBoundsChanged = true;
}
/**
* {@inheritDoc}
*/
@Override
public void draw(Canvas canvas) {
super.draw(canvas);
if (mForeground != null) {
final Drawable foreground = mForeground;
if (mForegroundBoundsChanged) {
mForegroundBoundsChanged = false;
final Rect selfBounds = mSelfBounds;
final Rect overlayBounds = mOverlayBounds;
final int w = mRight-mLeft;
final int h = mBottom-mTop;
if (mForegroundInPadding) {
selfBounds.set(0, 0, w, h);
} else {
selfBounds.set(mPaddingLeft, mPaddingTop, w - mPaddingRight, h - mPaddingBottom);
}
final int layoutDirection = getLayoutDirection();
Gravity.apply(mForegroundGravity, foreground.getIntrinsicWidth(),
foreground.getIntrinsicHeight(), selfBounds, overlayBounds,
layoutDirection);
foreground.setBounds(overlayBounds);
}
foreground.draw(canvas);
}
}
/**
* {@inheritDoc}
*/
@Override
public boolean gatherTransparentRegion(Region region) {
boolean opaque = super.gatherTransparentRegion(region);
if (region != null && mForeground != null) {
applyDrawableToTransparentRegion(mForeground, region);
}
return opaque;
}
/**
* Sets whether to consider all children, or just those in
* the VISIBLE or INVISIBLE state, when measuring. Defaults to false.
*
* @param measureAll true to consider children marked GONE, false otherwise.
* Default value is false.
*
* @attr ref android.R.styleable#FrameLayout_measureAllChildren
*/
@android.view.RemotableViewMethod
public void setMeasureAllChildren(boolean measureAll) {
mMeasureAllChildren = measureAll;
}
/**
* Determines whether all children, or just those in the VISIBLE or
* INVISIBLE state, are considered when measuring.
*
* @return Whether all children are considered when measuring.
*
* @deprecated This method is deprecated in favor of
* {@link #getMeasureAllChildren() getMeasureAllChildren()}, which was
* renamed for consistency with
* {@link #setMeasureAllChildren(boolean) setMeasureAllChildren()}.
*/
@Deprecated
public boolean getConsiderGoneChildrenWhenMeasuring() {
return getMeasureAllChildren();
}
/**
* Determines whether all children, or just those in the VISIBLE or
* INVISIBLE state, are considered when measuring.
*
* @return Whether all children are considered when measuring.
*/
public boolean getMeasureAllChildren() {
return mMeasureAllChildren;
}
/**
* {@inheritDoc}
*/
@Override
public LayoutParams generateLayoutParams(AttributeSet attrs) {
return new FrameLayout.LayoutParams(getContext(), attrs);
}
@Override
public boolean shouldDelayChildPressedState() {
return false;
}
/**
* {@inheritDoc}
*/
@Override
protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
return p instanceof LayoutParams;
}
@Override
protected ViewGroup.LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) {
return new LayoutParams(p);
}
@Override
public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
super.onInitializeAccessibilityEvent(event);
event.setClassName(FrameLayout.class.getName());
}
@Override
public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
super.onInitializeAccessibilityNodeInfo(info);
info.setClassName(FrameLayout.class.getName());
}
/**
* Per-child layout information for layouts that support margins.
* See {@link android.R.styleable#FrameLayout_Layout FrameLayout Layout Attributes}
* for a list of all child view attributes that this class supports.
*
* @attr ref android.R.styleable#FrameLayout_Layout_layout_gravity
*/
public static class LayoutParams extends MarginLayoutParams {
/**
* The gravity to apply with the View to which these layout parameters
* are associated.
*
* @see android.view.Gravity
*
* @attr ref android.R.styleable#FrameLayout_Layout_layout_gravity
*/
public int gravity = -1;
/**
* {@inheritDoc}
*/
public LayoutParams(Context c, AttributeSet attrs) {
super(c, attrs);
TypedArray a = c.obtainStyledAttributes(attrs, com.android.internal.R.styleable.FrameLayout_Layout);
gravity = a.getInt(com.android.internal.R.styleable.FrameLayout_Layout_layout_gravity, -1);
a.recycle();
}
/**
* {@inheritDoc}
*/
public LayoutParams(int width, int height) {
super(width, height);
}
/**
* Creates a new set of layout parameters with the specified width, height
* and weight.
*
* @param width the width, either {@link #MATCH_PARENT},
* {@link #WRAP_CONTENT} or a fixed size in pixels
* @param height the height, either {@link #MATCH_PARENT},
* {@link #WRAP_CONTENT} or a fixed size in pixels
* @param gravity the gravity
*
* @see android.view.Gravity
*/
public LayoutParams(int width, int height, int gravity) {
super(width, height);
this.gravity = gravity;
}
/**
* {@inheritDoc}
*/
public LayoutParams(ViewGroup.LayoutParams source) {
super(source);
}
/**
* {@inheritDoc}
*/
public LayoutParams(ViewGroup.MarginLayoutParams source) {
super(source);
}
}
}