| /* |
| * Copyright (C) 2007 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.annotation.Widget; |
| import android.content.Context; |
| import android.content.res.TypedArray; |
| import android.graphics.Rect; |
| import android.os.Bundle; |
| import android.util.AttributeSet; |
| import android.util.Log; |
| import android.view.ContextMenu.ContextMenuInfo; |
| import android.view.GestureDetector; |
| import android.view.Gravity; |
| import android.view.HapticFeedbackConstants; |
| import android.view.KeyEvent; |
| import android.view.MotionEvent; |
| import android.view.SoundEffectConstants; |
| import android.view.View; |
| import android.view.ViewConfiguration; |
| import android.view.ViewGroup; |
| import android.view.accessibility.AccessibilityEvent; |
| import android.view.accessibility.AccessibilityNodeInfo; |
| import android.view.animation.Transformation; |
| |
| import com.android.internal.R; |
| |
| /** |
| * A view that shows items in a center-locked, horizontally scrolling list. |
| * <p> |
| * The default values for the Gallery assume you will be using |
| * {@link android.R.styleable#Theme_galleryItemBackground} as the background for |
| * each View given to the Gallery from the Adapter. If you are not doing this, |
| * you may need to adjust some Gallery properties, such as the spacing. |
| * <p> |
| * Views given to the Gallery should use {@link Gallery.LayoutParams} as their |
| * layout parameters type. |
| * |
| * @attr ref android.R.styleable#Gallery_animationDuration |
| * @attr ref android.R.styleable#Gallery_spacing |
| * @attr ref android.R.styleable#Gallery_gravity |
| * |
| * @deprecated This widget is no longer supported. Other horizontally scrolling |
| * widgets include {@link HorizontalScrollView} and {@link android.support.v4.view.ViewPager} |
| * from the support library. |
| */ |
| @Deprecated |
| @Widget |
| public class Gallery extends AbsSpinner implements GestureDetector.OnGestureListener { |
| |
| private static final String TAG = "Gallery"; |
| |
| private static final boolean localLOGV = false; |
| |
| /** |
| * Duration in milliseconds from the start of a scroll during which we're |
| * unsure whether the user is scrolling or flinging. |
| */ |
| private static final int SCROLL_TO_FLING_UNCERTAINTY_TIMEOUT = 250; |
| |
| /** |
| * Horizontal spacing between items. |
| */ |
| private int mSpacing = 0; |
| |
| /** |
| * How long the transition animation should run when a child view changes |
| * position, measured in milliseconds. |
| */ |
| private int mAnimationDuration = 400; |
| |
| /** |
| * The alpha of items that are not selected. |
| */ |
| private float mUnselectedAlpha; |
| |
| /** |
| * Left most edge of a child seen so far during layout. |
| */ |
| private int mLeftMost; |
| |
| /** |
| * Right most edge of a child seen so far during layout. |
| */ |
| private int mRightMost; |
| |
| private int mGravity; |
| |
| /** |
| * Helper for detecting touch gestures. |
| */ |
| private GestureDetector mGestureDetector; |
| |
| /** |
| * The position of the item that received the user's down touch. |
| */ |
| private int mDownTouchPosition; |
| |
| /** |
| * The view of the item that received the user's down touch. |
| */ |
| private View mDownTouchView; |
| |
| /** |
| * Executes the delta scrolls from a fling or scroll movement. |
| */ |
| private FlingRunnable mFlingRunnable = new FlingRunnable(); |
| |
| /** |
| * Sets mSuppressSelectionChanged = false. This is used to set it to false |
| * in the future. It will also trigger a selection changed. |
| */ |
| private Runnable mDisableSuppressSelectionChangedRunnable = new Runnable() { |
| @Override |
| public void run() { |
| mSuppressSelectionChanged = false; |
| selectionChanged(); |
| } |
| }; |
| |
| /** |
| * When fling runnable runs, it resets this to false. Any method along the |
| * path until the end of its run() can set this to true to abort any |
| * remaining fling. For example, if we've reached either the leftmost or |
| * rightmost item, we will set this to true. |
| */ |
| private boolean mShouldStopFling; |
| |
| /** |
| * The currently selected item's child. |
| */ |
| private View mSelectedChild; |
| |
| /** |
| * Whether to continuously callback on the item selected listener during a |
| * fling. |
| */ |
| private boolean mShouldCallbackDuringFling = true; |
| |
| /** |
| * Whether to callback when an item that is not selected is clicked. |
| */ |
| private boolean mShouldCallbackOnUnselectedItemClick = true; |
| |
| /** |
| * If true, do not callback to item selected listener. |
| */ |
| private boolean mSuppressSelectionChanged; |
| |
| /** |
| * If true, we have received the "invoke" (center or enter buttons) key |
| * down. This is checked before we action on the "invoke" key up, and is |
| * subsequently cleared. |
| */ |
| private boolean mReceivedInvokeKeyDown; |
| |
| private AdapterContextMenuInfo mContextMenuInfo; |
| |
| /** |
| * If true, this onScroll is the first for this user's drag (remember, a |
| * drag sends many onScrolls). |
| */ |
| private boolean mIsFirstScroll; |
| |
| /** |
| * If true, mFirstPosition is the position of the rightmost child, and |
| * the children are ordered right to left. |
| */ |
| private boolean mIsRtl = true; |
| |
| /** |
| * Offset between the center of the selected child view and the center of the Gallery. |
| * Used to reset position correctly during layout. |
| */ |
| private int mSelectedCenterOffset; |
| |
| public Gallery(Context context) { |
| this(context, null); |
| } |
| |
| public Gallery(Context context, AttributeSet attrs) { |
| this(context, attrs, R.attr.galleryStyle); |
| } |
| |
| public Gallery(Context context, AttributeSet attrs, int defStyle) { |
| super(context, attrs, defStyle); |
| |
| mGestureDetector = new GestureDetector(context, this); |
| mGestureDetector.setIsLongpressEnabled(true); |
| |
| TypedArray a = context.obtainStyledAttributes( |
| attrs, com.android.internal.R.styleable.Gallery, defStyle, 0); |
| |
| int index = a.getInt(com.android.internal.R.styleable.Gallery_gravity, -1); |
| if (index >= 0) { |
| setGravity(index); |
| } |
| |
| int animationDuration = |
| a.getInt(com.android.internal.R.styleable.Gallery_animationDuration, -1); |
| if (animationDuration > 0) { |
| setAnimationDuration(animationDuration); |
| } |
| |
| int spacing = |
| a.getDimensionPixelOffset(com.android.internal.R.styleable.Gallery_spacing, 0); |
| setSpacing(spacing); |
| |
| float unselectedAlpha = a.getFloat( |
| com.android.internal.R.styleable.Gallery_unselectedAlpha, 0.5f); |
| setUnselectedAlpha(unselectedAlpha); |
| |
| a.recycle(); |
| |
| // We draw the selected item last (because otherwise the item to the |
| // right overlaps it) |
| mGroupFlags |= FLAG_USE_CHILD_DRAWING_ORDER; |
| |
| mGroupFlags |= FLAG_SUPPORT_STATIC_TRANSFORMATIONS; |
| } |
| |
| /** |
| * Whether or not to callback on any {@link #getOnItemSelectedListener()} |
| * while the items are being flinged. If false, only the final selected item |
| * will cause the callback. If true, all items between the first and the |
| * final will cause callbacks. |
| * |
| * @param shouldCallback Whether or not to callback on the listener while |
| * the items are being flinged. |
| */ |
| public void setCallbackDuringFling(boolean shouldCallback) { |
| mShouldCallbackDuringFling = shouldCallback; |
| } |
| |
| /** |
| * Whether or not to callback when an item that is not selected is clicked. |
| * If false, the item will become selected (and re-centered). If true, the |
| * {@link #getOnItemClickListener()} will get the callback. |
| * |
| * @param shouldCallback Whether or not to callback on the listener when a |
| * item that is not selected is clicked. |
| * @hide |
| */ |
| public void setCallbackOnUnselectedItemClick(boolean shouldCallback) { |
| mShouldCallbackOnUnselectedItemClick = shouldCallback; |
| } |
| |
| /** |
| * Sets how long the transition animation should run when a child view |
| * changes position. Only relevant if animation is turned on. |
| * |
| * @param animationDurationMillis The duration of the transition, in |
| * milliseconds. |
| * |
| * @attr ref android.R.styleable#Gallery_animationDuration |
| */ |
| public void setAnimationDuration(int animationDurationMillis) { |
| mAnimationDuration = animationDurationMillis; |
| } |
| |
| /** |
| * Sets the spacing between items in a Gallery |
| * |
| * @param spacing The spacing in pixels between items in the Gallery |
| * |
| * @attr ref android.R.styleable#Gallery_spacing |
| */ |
| public void setSpacing(int spacing) { |
| mSpacing = spacing; |
| } |
| |
| /** |
| * Sets the alpha of items that are not selected in the Gallery. |
| * |
| * @param unselectedAlpha the alpha for the items that are not selected. |
| * |
| * @attr ref android.R.styleable#Gallery_unselectedAlpha |
| */ |
| public void setUnselectedAlpha(float unselectedAlpha) { |
| mUnselectedAlpha = unselectedAlpha; |
| } |
| |
| @Override |
| protected boolean getChildStaticTransformation(View child, Transformation t) { |
| |
| t.clear(); |
| t.setAlpha(child == mSelectedChild ? 1.0f : mUnselectedAlpha); |
| |
| return true; |
| } |
| |
| @Override |
| protected int computeHorizontalScrollExtent() { |
| // Only 1 item is considered to be selected |
| return 1; |
| } |
| |
| @Override |
| protected int computeHorizontalScrollOffset() { |
| // Current scroll position is the same as the selected position |
| return mSelectedPosition; |
| } |
| |
| @Override |
| protected int computeHorizontalScrollRange() { |
| // Scroll range is the same as the item count |
| return mItemCount; |
| } |
| |
| @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 ViewGroup.LayoutParams generateLayoutParams(AttributeSet attrs) { |
| return new LayoutParams(getContext(), attrs); |
| } |
| |
| @Override |
| protected ViewGroup.LayoutParams generateDefaultLayoutParams() { |
| /* |
| * Gallery expects Gallery.LayoutParams. |
| */ |
| return new Gallery.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, |
| ViewGroup.LayoutParams.WRAP_CONTENT); |
| } |
| |
| @Override |
| protected void onLayout(boolean changed, int l, int t, int r, int b) { |
| super.onLayout(changed, l, t, r, b); |
| |
| /* |
| * Remember that we are in layout to prevent more layout request from |
| * being generated. |
| */ |
| mInLayout = true; |
| layout(0, false); |
| mInLayout = false; |
| } |
| |
| @Override |
| int getChildHeight(View child) { |
| return child.getMeasuredHeight(); |
| } |
| |
| /** |
| * Tracks a motion scroll. In reality, this is used to do just about any |
| * movement to items (touch scroll, arrow-key scroll, set an item as selected). |
| * |
| * @param deltaX Change in X from the previous event. |
| */ |
| void trackMotionScroll(int deltaX) { |
| |
| if (getChildCount() == 0) { |
| return; |
| } |
| |
| boolean toLeft = deltaX < 0; |
| |
| int limitedDeltaX = getLimitedMotionScrollAmount(toLeft, deltaX); |
| if (limitedDeltaX != deltaX) { |
| // The above call returned a limited amount, so stop any scrolls/flings |
| mFlingRunnable.endFling(false); |
| onFinishedMovement(); |
| } |
| |
| offsetChildrenLeftAndRight(limitedDeltaX); |
| |
| detachOffScreenChildren(toLeft); |
| |
| if (toLeft) { |
| // If moved left, there will be empty space on the right |
| fillToGalleryRight(); |
| } else { |
| // Similarly, empty space on the left |
| fillToGalleryLeft(); |
| } |
| |
| // Clear unused views |
| mRecycler.clear(); |
| |
| setSelectionToCenterChild(); |
| |
| final View selChild = mSelectedChild; |
| if (selChild != null) { |
| final int childLeft = selChild.getLeft(); |
| final int childCenter = selChild.getWidth() / 2; |
| final int galleryCenter = getWidth() / 2; |
| mSelectedCenterOffset = childLeft + childCenter - galleryCenter; |
| } |
| |
| onScrollChanged(0, 0, 0, 0); // dummy values, View's implementation does not use these. |
| |
| invalidate(); |
| } |
| |
| int getLimitedMotionScrollAmount(boolean motionToLeft, int deltaX) { |
| int extremeItemPosition = motionToLeft != mIsRtl ? mItemCount - 1 : 0; |
| View extremeChild = getChildAt(extremeItemPosition - mFirstPosition); |
| |
| if (extremeChild == null) { |
| return deltaX; |
| } |
| |
| int extremeChildCenter = getCenterOfView(extremeChild); |
| int galleryCenter = getCenterOfGallery(); |
| |
| if (motionToLeft) { |
| if (extremeChildCenter <= galleryCenter) { |
| |
| // The extreme child is past his boundary point! |
| return 0; |
| } |
| } else { |
| if (extremeChildCenter >= galleryCenter) { |
| |
| // The extreme child is past his boundary point! |
| return 0; |
| } |
| } |
| |
| int centerDifference = galleryCenter - extremeChildCenter; |
| |
| return motionToLeft |
| ? Math.max(centerDifference, deltaX) |
| : Math.min(centerDifference, deltaX); |
| } |
| |
| /** |
| * Offset the horizontal location of all children of this view by the |
| * specified number of pixels. |
| * |
| * @param offset the number of pixels to offset |
| */ |
| private void offsetChildrenLeftAndRight(int offset) { |
| for (int i = getChildCount() - 1; i >= 0; i--) { |
| getChildAt(i).offsetLeftAndRight(offset); |
| } |
| } |
| |
| /** |
| * @return The center of this Gallery. |
| */ |
| private int getCenterOfGallery() { |
| return (getWidth() - mPaddingLeft - mPaddingRight) / 2 + mPaddingLeft; |
| } |
| |
| /** |
| * @return The center of the given view. |
| */ |
| private static int getCenterOfView(View view) { |
| return view.getLeft() + view.getWidth() / 2; |
| } |
| |
| /** |
| * Detaches children that are off the screen (i.e.: Gallery bounds). |
| * |
| * @param toLeft Whether to detach children to the left of the Gallery, or |
| * to the right. |
| */ |
| private void detachOffScreenChildren(boolean toLeft) { |
| int numChildren = getChildCount(); |
| int firstPosition = mFirstPosition; |
| int start = 0; |
| int count = 0; |
| |
| if (toLeft) { |
| final int galleryLeft = mPaddingLeft; |
| for (int i = 0; i < numChildren; i++) { |
| int n = mIsRtl ? (numChildren - 1 - i) : i; |
| final View child = getChildAt(n); |
| if (child.getRight() >= galleryLeft) { |
| break; |
| } else { |
| start = n; |
| count++; |
| mRecycler.put(firstPosition + n, child); |
| } |
| } |
| if (!mIsRtl) { |
| start = 0; |
| } |
| } else { |
| final int galleryRight = getWidth() - mPaddingRight; |
| for (int i = numChildren - 1; i >= 0; i--) { |
| int n = mIsRtl ? numChildren - 1 - i : i; |
| final View child = getChildAt(n); |
| if (child.getLeft() <= galleryRight) { |
| break; |
| } else { |
| start = n; |
| count++; |
| mRecycler.put(firstPosition + n, child); |
| } |
| } |
| if (mIsRtl) { |
| start = 0; |
| } |
| } |
| |
| detachViewsFromParent(start, count); |
| |
| if (toLeft != mIsRtl) { |
| mFirstPosition += count; |
| } |
| } |
| |
| /** |
| * Scrolls the items so that the selected item is in its 'slot' (its center |
| * is the gallery's center). |
| */ |
| private void scrollIntoSlots() { |
| |
| if (getChildCount() == 0 || mSelectedChild == null) return; |
| |
| int selectedCenter = getCenterOfView(mSelectedChild); |
| int targetCenter = getCenterOfGallery(); |
| |
| int scrollAmount = targetCenter - selectedCenter; |
| if (scrollAmount != 0) { |
| mFlingRunnable.startUsingDistance(scrollAmount); |
| } else { |
| onFinishedMovement(); |
| } |
| } |
| |
| private void onFinishedMovement() { |
| if (mSuppressSelectionChanged) { |
| mSuppressSelectionChanged = false; |
| |
| // We haven't been callbacking during the fling, so do it now |
| super.selectionChanged(); |
| } |
| mSelectedCenterOffset = 0; |
| invalidate(); |
| } |
| |
| @Override |
| void selectionChanged() { |
| if (!mSuppressSelectionChanged) { |
| super.selectionChanged(); |
| } |
| } |
| |
| /** |
| * Looks for the child that is closest to the center and sets it as the |
| * selected child. |
| */ |
| private void setSelectionToCenterChild() { |
| |
| View selView = mSelectedChild; |
| if (mSelectedChild == null) return; |
| |
| int galleryCenter = getCenterOfGallery(); |
| |
| // Common case where the current selected position is correct |
| if (selView.getLeft() <= galleryCenter && selView.getRight() >= galleryCenter) { |
| return; |
| } |
| |
| // TODO better search |
| int closestEdgeDistance = Integer.MAX_VALUE; |
| int newSelectedChildIndex = 0; |
| for (int i = getChildCount() - 1; i >= 0; i--) { |
| |
| View child = getChildAt(i); |
| |
| if (child.getLeft() <= galleryCenter && child.getRight() >= galleryCenter) { |
| // This child is in the center |
| newSelectedChildIndex = i; |
| break; |
| } |
| |
| int childClosestEdgeDistance = Math.min(Math.abs(child.getLeft() - galleryCenter), |
| Math.abs(child.getRight() - galleryCenter)); |
| if (childClosestEdgeDistance < closestEdgeDistance) { |
| closestEdgeDistance = childClosestEdgeDistance; |
| newSelectedChildIndex = i; |
| } |
| } |
| |
| int newPos = mFirstPosition + newSelectedChildIndex; |
| |
| if (newPos != mSelectedPosition) { |
| setSelectedPositionInt(newPos); |
| setNextSelectedPositionInt(newPos); |
| checkSelectionChanged(); |
| } |
| } |
| |
| /** |
| * Creates and positions all views for this Gallery. |
| * <p> |
| * We layout rarely, most of the time {@link #trackMotionScroll(int)} takes |
| * care of repositioning, adding, and removing children. |
| * |
| * @param delta Change in the selected position. +1 means the selection is |
| * moving to the right, so views are scrolling to the left. -1 |
| * means the selection is moving to the left. |
| */ |
| @Override |
| void layout(int delta, boolean animate) { |
| |
| mIsRtl = isLayoutRtl(); |
| |
| int childrenLeft = mSpinnerPadding.left; |
| int childrenWidth = mRight - mLeft - mSpinnerPadding.left - mSpinnerPadding.right; |
| |
| if (mDataChanged) { |
| handleDataChanged(); |
| } |
| |
| // Handle an empty gallery by removing all views. |
| if (mItemCount == 0) { |
| resetList(); |
| return; |
| } |
| |
| // Update to the new selected position. |
| if (mNextSelectedPosition >= 0) { |
| setSelectedPositionInt(mNextSelectedPosition); |
| } |
| |
| // All views go in recycler while we are in layout |
| recycleAllViews(); |
| |
| // Clear out old views |
| //removeAllViewsInLayout(); |
| detachAllViewsFromParent(); |
| |
| /* |
| * These will be used to give initial positions to views entering the |
| * gallery as we scroll |
| */ |
| mRightMost = 0; |
| mLeftMost = 0; |
| |
| // Make selected view and center it |
| |
| /* |
| * mFirstPosition will be decreased as we add views to the left later |
| * on. The 0 for x will be offset in a couple lines down. |
| */ |
| mFirstPosition = mSelectedPosition; |
| View sel = makeAndAddView(mSelectedPosition, 0, 0, true); |
| |
| // Put the selected child in the center |
| int selectedOffset = childrenLeft + (childrenWidth / 2) - (sel.getWidth() / 2) + |
| mSelectedCenterOffset; |
| sel.offsetLeftAndRight(selectedOffset); |
| |
| fillToGalleryRight(); |
| fillToGalleryLeft(); |
| |
| // Flush any cached views that did not get reused above |
| mRecycler.clear(); |
| |
| invalidate(); |
| checkSelectionChanged(); |
| |
| mDataChanged = false; |
| mNeedSync = false; |
| setNextSelectedPositionInt(mSelectedPosition); |
| |
| updateSelectedItemMetadata(); |
| } |
| |
| private void fillToGalleryLeft() { |
| if (mIsRtl) { |
| fillToGalleryLeftRtl(); |
| } else { |
| fillToGalleryLeftLtr(); |
| } |
| } |
| |
| private void fillToGalleryLeftRtl() { |
| int itemSpacing = mSpacing; |
| int galleryLeft = mPaddingLeft; |
| int numChildren = getChildCount(); |
| int numItems = mItemCount; |
| |
| // Set state for initial iteration |
| View prevIterationView = getChildAt(numChildren - 1); |
| int curPosition; |
| int curRightEdge; |
| |
| if (prevIterationView != null) { |
| curPosition = mFirstPosition + numChildren; |
| curRightEdge = prevIterationView.getLeft() - itemSpacing; |
| } else { |
| // No children available! |
| mFirstPosition = curPosition = mItemCount - 1; |
| curRightEdge = mRight - mLeft - mPaddingRight; |
| mShouldStopFling = true; |
| } |
| |
| while (curRightEdge > galleryLeft && curPosition < mItemCount) { |
| prevIterationView = makeAndAddView(curPosition, curPosition - mSelectedPosition, |
| curRightEdge, false); |
| |
| // Set state for next iteration |
| curRightEdge = prevIterationView.getLeft() - itemSpacing; |
| curPosition++; |
| } |
| } |
| |
| private void fillToGalleryLeftLtr() { |
| int itemSpacing = mSpacing; |
| int galleryLeft = mPaddingLeft; |
| |
| // Set state for initial iteration |
| View prevIterationView = getChildAt(0); |
| int curPosition; |
| int curRightEdge; |
| |
| if (prevIterationView != null) { |
| curPosition = mFirstPosition - 1; |
| curRightEdge = prevIterationView.getLeft() - itemSpacing; |
| } else { |
| // No children available! |
| curPosition = 0; |
| curRightEdge = mRight - mLeft - mPaddingRight; |
| mShouldStopFling = true; |
| } |
| |
| while (curRightEdge > galleryLeft && curPosition >= 0) { |
| prevIterationView = makeAndAddView(curPosition, curPosition - mSelectedPosition, |
| curRightEdge, false); |
| |
| // Remember some state |
| mFirstPosition = curPosition; |
| |
| // Set state for next iteration |
| curRightEdge = prevIterationView.getLeft() - itemSpacing; |
| curPosition--; |
| } |
| } |
| |
| private void fillToGalleryRight() { |
| if (mIsRtl) { |
| fillToGalleryRightRtl(); |
| } else { |
| fillToGalleryRightLtr(); |
| } |
| } |
| |
| private void fillToGalleryRightRtl() { |
| int itemSpacing = mSpacing; |
| int galleryRight = mRight - mLeft - mPaddingRight; |
| |
| // Set state for initial iteration |
| View prevIterationView = getChildAt(0); |
| int curPosition; |
| int curLeftEdge; |
| |
| if (prevIterationView != null) { |
| curPosition = mFirstPosition -1; |
| curLeftEdge = prevIterationView.getRight() + itemSpacing; |
| } else { |
| curPosition = 0; |
| curLeftEdge = mPaddingLeft; |
| mShouldStopFling = true; |
| } |
| |
| while (curLeftEdge < galleryRight && curPosition >= 0) { |
| prevIterationView = makeAndAddView(curPosition, curPosition - mSelectedPosition, |
| curLeftEdge, true); |
| |
| // Remember some state |
| mFirstPosition = curPosition; |
| |
| // Set state for next iteration |
| curLeftEdge = prevIterationView.getRight() + itemSpacing; |
| curPosition--; |
| } |
| } |
| |
| private void fillToGalleryRightLtr() { |
| int itemSpacing = mSpacing; |
| int galleryRight = mRight - mLeft - mPaddingRight; |
| int numChildren = getChildCount(); |
| int numItems = mItemCount; |
| |
| // Set state for initial iteration |
| View prevIterationView = getChildAt(numChildren - 1); |
| int curPosition; |
| int curLeftEdge; |
| |
| if (prevIterationView != null) { |
| curPosition = mFirstPosition + numChildren; |
| curLeftEdge = prevIterationView.getRight() + itemSpacing; |
| } else { |
| mFirstPosition = curPosition = mItemCount - 1; |
| curLeftEdge = mPaddingLeft; |
| mShouldStopFling = true; |
| } |
| |
| while (curLeftEdge < galleryRight && curPosition < numItems) { |
| prevIterationView = makeAndAddView(curPosition, curPosition - mSelectedPosition, |
| curLeftEdge, true); |
| |
| // Set state for next iteration |
| curLeftEdge = prevIterationView.getRight() + itemSpacing; |
| curPosition++; |
| } |
| } |
| |
| /** |
| * Obtain a view, either by pulling an existing view from the recycler or by |
| * getting a new one from the adapter. If we are animating, make sure there |
| * is enough information in the view's layout parameters to animate from the |
| * old to new positions. |
| * |
| * @param position Position in the gallery for the view to obtain |
| * @param offset Offset from the selected position |
| * @param x X-coordinate indicating where this view should be placed. This |
| * will either be the left or right edge of the view, depending on |
| * the fromLeft parameter |
| * @param fromLeft Are we positioning views based on the left edge? (i.e., |
| * building from left to right)? |
| * @return A view that has been added to the gallery |
| */ |
| private View makeAndAddView(int position, int offset, int x, boolean fromLeft) { |
| |
| View child; |
| if (!mDataChanged) { |
| child = mRecycler.get(position); |
| if (child != null) { |
| // Can reuse an existing view |
| int childLeft = child.getLeft(); |
| |
| // Remember left and right edges of where views have been placed |
| mRightMost = Math.max(mRightMost, childLeft |
| + child.getMeasuredWidth()); |
| mLeftMost = Math.min(mLeftMost, childLeft); |
| |
| // Position the view |
| setUpChild(child, offset, x, fromLeft); |
| |
| return child; |
| } |
| } |
| |
| // Nothing found in the recycler -- ask the adapter for a view |
| child = mAdapter.getView(position, null, this); |
| |
| // Position the view |
| setUpChild(child, offset, x, fromLeft); |
| |
| return child; |
| } |
| |
| /** |
| * Helper for makeAndAddView to set the position of a view and fill out its |
| * layout parameters. |
| * |
| * @param child The view to position |
| * @param offset Offset from the selected position |
| * @param x X-coordinate indicating where this view should be placed. This |
| * will either be the left or right edge of the view, depending on |
| * the fromLeft parameter |
| * @param fromLeft Are we positioning views based on the left edge? (i.e., |
| * building from left to right)? |
| */ |
| private void setUpChild(View child, int offset, int x, boolean fromLeft) { |
| |
| // Respect layout params that are already in the view. Otherwise |
| // make some up... |
| Gallery.LayoutParams lp = (Gallery.LayoutParams) child.getLayoutParams(); |
| if (lp == null) { |
| lp = (Gallery.LayoutParams) generateDefaultLayoutParams(); |
| } |
| |
| addViewInLayout(child, fromLeft != mIsRtl ? -1 : 0, lp); |
| |
| child.setSelected(offset == 0); |
| |
| // Get measure specs |
| int childHeightSpec = ViewGroup.getChildMeasureSpec(mHeightMeasureSpec, |
| mSpinnerPadding.top + mSpinnerPadding.bottom, lp.height); |
| int childWidthSpec = ViewGroup.getChildMeasureSpec(mWidthMeasureSpec, |
| mSpinnerPadding.left + mSpinnerPadding.right, lp.width); |
| |
| // Measure child |
| child.measure(childWidthSpec, childHeightSpec); |
| |
| int childLeft; |
| int childRight; |
| |
| // Position vertically based on gravity setting |
| int childTop = calculateTop(child, true); |
| int childBottom = childTop + child.getMeasuredHeight(); |
| |
| int width = child.getMeasuredWidth(); |
| if (fromLeft) { |
| childLeft = x; |
| childRight = childLeft + width; |
| } else { |
| childLeft = x - width; |
| childRight = x; |
| } |
| |
| child.layout(childLeft, childTop, childRight, childBottom); |
| } |
| |
| /** |
| * Figure out vertical placement based on mGravity |
| * |
| * @param child Child to place |
| * @return Where the top of the child should be |
| */ |
| private int calculateTop(View child, boolean duringLayout) { |
| int myHeight = duringLayout ? getMeasuredHeight() : getHeight(); |
| int childHeight = duringLayout ? child.getMeasuredHeight() : child.getHeight(); |
| |
| int childTop = 0; |
| |
| switch (mGravity) { |
| case Gravity.TOP: |
| childTop = mSpinnerPadding.top; |
| break; |
| case Gravity.CENTER_VERTICAL: |
| int availableSpace = myHeight - mSpinnerPadding.bottom |
| - mSpinnerPadding.top - childHeight; |
| childTop = mSpinnerPadding.top + (availableSpace / 2); |
| break; |
| case Gravity.BOTTOM: |
| childTop = myHeight - mSpinnerPadding.bottom - childHeight; |
| break; |
| } |
| return childTop; |
| } |
| |
| @Override |
| public boolean onTouchEvent(MotionEvent event) { |
| |
| // Give everything to the gesture detector |
| boolean retValue = mGestureDetector.onTouchEvent(event); |
| |
| int action = event.getAction(); |
| if (action == MotionEvent.ACTION_UP) { |
| // Helper method for lifted finger |
| onUp(); |
| } else if (action == MotionEvent.ACTION_CANCEL) { |
| onCancel(); |
| } |
| |
| return retValue; |
| } |
| |
| @Override |
| public boolean onSingleTapUp(MotionEvent e) { |
| |
| if (mDownTouchPosition >= 0) { |
| |
| // An item tap should make it selected, so scroll to this child. |
| scrollToChild(mDownTouchPosition - mFirstPosition); |
| |
| // Also pass the click so the client knows, if it wants to. |
| if (mShouldCallbackOnUnselectedItemClick || mDownTouchPosition == mSelectedPosition) { |
| performItemClick(mDownTouchView, mDownTouchPosition, mAdapter |
| .getItemId(mDownTouchPosition)); |
| } |
| |
| return true; |
| } |
| |
| return false; |
| } |
| |
| @Override |
| public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) { |
| |
| if (!mShouldCallbackDuringFling) { |
| // We want to suppress selection changes |
| |
| // Remove any future code to set mSuppressSelectionChanged = false |
| removeCallbacks(mDisableSuppressSelectionChangedRunnable); |
| |
| // This will get reset once we scroll into slots |
| if (!mSuppressSelectionChanged) mSuppressSelectionChanged = true; |
| } |
| |
| // Fling the gallery! |
| mFlingRunnable.startUsingVelocity((int) -velocityX); |
| |
| return true; |
| } |
| |
| @Override |
| public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) { |
| |
| if (localLOGV) Log.v(TAG, String.valueOf(e2.getX() - e1.getX())); |
| |
| /* |
| * Now's a good time to tell our parent to stop intercepting our events! |
| * The user has moved more than the slop amount, since GestureDetector |
| * ensures this before calling this method. Also, if a parent is more |
| * interested in this touch's events than we are, it would have |
| * intercepted them by now (for example, we can assume when a Gallery is |
| * in the ListView, a vertical scroll would not end up in this method |
| * since a ListView would have intercepted it by now). |
| */ |
| mParent.requestDisallowInterceptTouchEvent(true); |
| |
| // As the user scrolls, we want to callback selection changes so related- |
| // info on the screen is up-to-date with the gallery's selection |
| if (!mShouldCallbackDuringFling) { |
| if (mIsFirstScroll) { |
| /* |
| * We're not notifying the client of selection changes during |
| * the fling, and this scroll could possibly be a fling. Don't |
| * do selection changes until we're sure it is not a fling. |
| */ |
| if (!mSuppressSelectionChanged) mSuppressSelectionChanged = true; |
| postDelayed(mDisableSuppressSelectionChangedRunnable, SCROLL_TO_FLING_UNCERTAINTY_TIMEOUT); |
| } |
| } else { |
| if (mSuppressSelectionChanged) mSuppressSelectionChanged = false; |
| } |
| |
| // Track the motion |
| trackMotionScroll(-1 * (int) distanceX); |
| |
| mIsFirstScroll = false; |
| return true; |
| } |
| |
| @Override |
| public boolean onDown(MotionEvent e) { |
| |
| // Kill any existing fling/scroll |
| mFlingRunnable.stop(false); |
| |
| // Get the item's view that was touched |
| mDownTouchPosition = pointToPosition((int) e.getX(), (int) e.getY()); |
| |
| if (mDownTouchPosition >= 0) { |
| mDownTouchView = getChildAt(mDownTouchPosition - mFirstPosition); |
| mDownTouchView.setPressed(true); |
| } |
| |
| // Reset the multiple-scroll tracking state |
| mIsFirstScroll = true; |
| |
| // Must return true to get matching events for this down event. |
| return true; |
| } |
| |
| /** |
| * Called when a touch event's action is MotionEvent.ACTION_UP. |
| */ |
| void onUp() { |
| |
| if (mFlingRunnable.mScroller.isFinished()) { |
| scrollIntoSlots(); |
| } |
| |
| dispatchUnpress(); |
| } |
| |
| /** |
| * Called when a touch event's action is MotionEvent.ACTION_CANCEL. |
| */ |
| void onCancel() { |
| onUp(); |
| } |
| |
| @Override |
| public void onLongPress(MotionEvent e) { |
| |
| if (mDownTouchPosition < 0) { |
| return; |
| } |
| |
| performHapticFeedback(HapticFeedbackConstants.LONG_PRESS); |
| long id = getItemIdAtPosition(mDownTouchPosition); |
| dispatchLongPress(mDownTouchView, mDownTouchPosition, id); |
| } |
| |
| // Unused methods from GestureDetector.OnGestureListener below |
| |
| @Override |
| public void onShowPress(MotionEvent e) { |
| } |
| |
| // Unused methods from GestureDetector.OnGestureListener above |
| |
| private void dispatchPress(View child) { |
| |
| if (child != null) { |
| child.setPressed(true); |
| } |
| |
| setPressed(true); |
| } |
| |
| private void dispatchUnpress() { |
| |
| for (int i = getChildCount() - 1; i >= 0; i--) { |
| getChildAt(i).setPressed(false); |
| } |
| |
| setPressed(false); |
| } |
| |
| @Override |
| public void dispatchSetSelected(boolean selected) { |
| /* |
| * We don't want to pass the selected state given from its parent to its |
| * children since this widget itself has a selected state to give to its |
| * children. |
| */ |
| } |
| |
| @Override |
| protected void dispatchSetPressed(boolean pressed) { |
| |
| // Show the pressed state on the selected child |
| if (mSelectedChild != null) { |
| mSelectedChild.setPressed(pressed); |
| } |
| } |
| |
| @Override |
| protected ContextMenuInfo getContextMenuInfo() { |
| return mContextMenuInfo; |
| } |
| |
| @Override |
| public boolean showContextMenuForChild(View originalView) { |
| |
| final int longPressPosition = getPositionForView(originalView); |
| if (longPressPosition < 0) { |
| return false; |
| } |
| |
| final long longPressId = mAdapter.getItemId(longPressPosition); |
| return dispatchLongPress(originalView, longPressPosition, longPressId); |
| } |
| |
| @Override |
| public boolean showContextMenu() { |
| |
| if (isPressed() && mSelectedPosition >= 0) { |
| int index = mSelectedPosition - mFirstPosition; |
| View v = getChildAt(index); |
| return dispatchLongPress(v, mSelectedPosition, mSelectedRowId); |
| } |
| |
| return false; |
| } |
| |
| private boolean dispatchLongPress(View view, int position, long id) { |
| boolean handled = false; |
| |
| if (mOnItemLongClickListener != null) { |
| handled = mOnItemLongClickListener.onItemLongClick(this, mDownTouchView, |
| mDownTouchPosition, id); |
| } |
| |
| if (!handled) { |
| mContextMenuInfo = new AdapterContextMenuInfo(view, position, id); |
| handled = super.showContextMenuForChild(this); |
| } |
| |
| if (handled) { |
| performHapticFeedback(HapticFeedbackConstants.LONG_PRESS); |
| } |
| |
| return handled; |
| } |
| |
| @Override |
| public boolean dispatchKeyEvent(KeyEvent event) { |
| // Gallery steals all key events |
| return event.dispatch(this, null, null); |
| } |
| |
| /** |
| * Handles left, right, and clicking |
| * @see android.view.View#onKeyDown |
| */ |
| @Override |
| public boolean onKeyDown(int keyCode, KeyEvent event) { |
| switch (keyCode) { |
| |
| case KeyEvent.KEYCODE_DPAD_LEFT: |
| if (movePrevious()) { |
| playSoundEffect(SoundEffectConstants.NAVIGATION_LEFT); |
| return true; |
| } |
| break; |
| case KeyEvent.KEYCODE_DPAD_RIGHT: |
| if (moveNext()) { |
| playSoundEffect(SoundEffectConstants.NAVIGATION_RIGHT); |
| return true; |
| } |
| break; |
| case KeyEvent.KEYCODE_DPAD_CENTER: |
| case KeyEvent.KEYCODE_ENTER: |
| mReceivedInvokeKeyDown = true; |
| // fallthrough to default handling |
| } |
| |
| return super.onKeyDown(keyCode, event); |
| } |
| |
| @Override |
| public boolean onKeyUp(int keyCode, KeyEvent event) { |
| switch (keyCode) { |
| case KeyEvent.KEYCODE_DPAD_CENTER: |
| case KeyEvent.KEYCODE_ENTER: { |
| |
| if (mReceivedInvokeKeyDown) { |
| if (mItemCount > 0) { |
| |
| dispatchPress(mSelectedChild); |
| postDelayed(new Runnable() { |
| @Override |
| public void run() { |
| dispatchUnpress(); |
| } |
| }, ViewConfiguration.getPressedStateDuration()); |
| |
| int selectedIndex = mSelectedPosition - mFirstPosition; |
| performItemClick(getChildAt(selectedIndex), mSelectedPosition, mAdapter |
| .getItemId(mSelectedPosition)); |
| } |
| } |
| |
| // Clear the flag |
| mReceivedInvokeKeyDown = false; |
| |
| return true; |
| } |
| } |
| |
| return super.onKeyUp(keyCode, event); |
| } |
| |
| boolean movePrevious() { |
| if (mItemCount > 0 && mSelectedPosition > 0) { |
| scrollToChild(mSelectedPosition - mFirstPosition - 1); |
| return true; |
| } else { |
| return false; |
| } |
| } |
| |
| boolean moveNext() { |
| if (mItemCount > 0 && mSelectedPosition < mItemCount - 1) { |
| scrollToChild(mSelectedPosition - mFirstPosition + 1); |
| return true; |
| } else { |
| return false; |
| } |
| } |
| |
| private boolean scrollToChild(int childPosition) { |
| View child = getChildAt(childPosition); |
| |
| if (child != null) { |
| int distance = getCenterOfGallery() - getCenterOfView(child); |
| mFlingRunnable.startUsingDistance(distance); |
| return true; |
| } |
| |
| return false; |
| } |
| |
| @Override |
| void setSelectedPositionInt(int position) { |
| super.setSelectedPositionInt(position); |
| |
| // Updates any metadata we keep about the selected item. |
| updateSelectedItemMetadata(); |
| } |
| |
| private void updateSelectedItemMetadata() { |
| |
| View oldSelectedChild = mSelectedChild; |
| |
| View child = mSelectedChild = getChildAt(mSelectedPosition - mFirstPosition); |
| if (child == null) { |
| return; |
| } |
| |
| child.setSelected(true); |
| child.setFocusable(true); |
| |
| if (hasFocus()) { |
| child.requestFocus(); |
| } |
| |
| // We unfocus the old child down here so the above hasFocus check |
| // returns true |
| if (oldSelectedChild != null && oldSelectedChild != child) { |
| |
| // Make sure its drawable state doesn't contain 'selected' |
| oldSelectedChild.setSelected(false); |
| |
| // Make sure it is not focusable anymore, since otherwise arrow keys |
| // can make this one be focused |
| oldSelectedChild.setFocusable(false); |
| } |
| |
| } |
| |
| /** |
| * Describes how the child views are aligned. |
| * @param gravity |
| * |
| * @attr ref android.R.styleable#Gallery_gravity |
| */ |
| public void setGravity(int gravity) |
| { |
| if (mGravity != gravity) { |
| mGravity = gravity; |
| requestLayout(); |
| } |
| } |
| |
| @Override |
| protected int getChildDrawingOrder(int childCount, int i) { |
| int selectedIndex = mSelectedPosition - mFirstPosition; |
| |
| // Just to be safe |
| if (selectedIndex < 0) return i; |
| |
| if (i == childCount - 1) { |
| // Draw the selected child last |
| return selectedIndex; |
| } else if (i >= selectedIndex) { |
| // Move the children after the selected child earlier one |
| return i + 1; |
| } else { |
| // Keep the children before the selected child the same |
| return i; |
| } |
| } |
| |
| @Override |
| protected void onFocusChanged(boolean gainFocus, int direction, Rect previouslyFocusedRect) { |
| super.onFocusChanged(gainFocus, direction, previouslyFocusedRect); |
| |
| /* |
| * The gallery shows focus by focusing the selected item. So, give |
| * focus to our selected item instead. We steal keys from our |
| * selected item elsewhere. |
| */ |
| if (gainFocus && mSelectedChild != null) { |
| mSelectedChild.requestFocus(direction); |
| mSelectedChild.setSelected(true); |
| } |
| |
| } |
| |
| @Override |
| public void onInitializeAccessibilityEvent(AccessibilityEvent event) { |
| super.onInitializeAccessibilityEvent(event); |
| event.setClassName(Gallery.class.getName()); |
| } |
| |
| @Override |
| public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) { |
| super.onInitializeAccessibilityNodeInfo(info); |
| info.setClassName(Gallery.class.getName()); |
| info.setScrollable(mItemCount > 1); |
| if (isEnabled()) { |
| if (mItemCount > 0 && mSelectedPosition < mItemCount - 1) { |
| info.addAction(AccessibilityNodeInfo.ACTION_SCROLL_FORWARD); |
| } |
| if (isEnabled() && mItemCount > 0 && mSelectedPosition > 0) { |
| info.addAction(AccessibilityNodeInfo.ACTION_SCROLL_BACKWARD); |
| } |
| } |
| } |
| |
| @Override |
| public boolean performAccessibilityAction(int action, Bundle arguments) { |
| if (super.performAccessibilityAction(action, arguments)) { |
| return true; |
| } |
| switch (action) { |
| case AccessibilityNodeInfo.ACTION_SCROLL_FORWARD: { |
| if (isEnabled() && mItemCount > 0 && mSelectedPosition < mItemCount - 1) { |
| final int currentChildIndex = mSelectedPosition - mFirstPosition; |
| return scrollToChild(currentChildIndex + 1); |
| } |
| } return false; |
| case AccessibilityNodeInfo.ACTION_SCROLL_BACKWARD: { |
| if (isEnabled() && mItemCount > 0 && mSelectedPosition > 0) { |
| final int currentChildIndex = mSelectedPosition - mFirstPosition; |
| return scrollToChild(currentChildIndex - 1); |
| } |
| } return false; |
| } |
| return false; |
| } |
| |
| /** |
| * Responsible for fling behavior. Use {@link #startUsingVelocity(int)} to |
| * initiate a fling. Each frame of the fling is handled in {@link #run()}. |
| * A FlingRunnable will keep re-posting itself until the fling is done. |
| */ |
| private class FlingRunnable implements Runnable { |
| /** |
| * Tracks the decay of a fling scroll |
| */ |
| private Scroller mScroller; |
| |
| /** |
| * X value reported by mScroller on the previous fling |
| */ |
| private int mLastFlingX; |
| |
| public FlingRunnable() { |
| mScroller = new Scroller(getContext()); |
| } |
| |
| private void startCommon() { |
| // Remove any pending flings |
| removeCallbacks(this); |
| } |
| |
| public void startUsingVelocity(int initialVelocity) { |
| if (initialVelocity == 0) return; |
| |
| startCommon(); |
| |
| int initialX = initialVelocity < 0 ? Integer.MAX_VALUE : 0; |
| mLastFlingX = initialX; |
| mScroller.fling(initialX, 0, initialVelocity, 0, |
| 0, Integer.MAX_VALUE, 0, Integer.MAX_VALUE); |
| post(this); |
| } |
| |
| public void startUsingDistance(int distance) { |
| if (distance == 0) return; |
| |
| startCommon(); |
| |
| mLastFlingX = 0; |
| mScroller.startScroll(0, 0, -distance, 0, mAnimationDuration); |
| post(this); |
| } |
| |
| public void stop(boolean scrollIntoSlots) { |
| removeCallbacks(this); |
| endFling(scrollIntoSlots); |
| } |
| |
| private void endFling(boolean scrollIntoSlots) { |
| /* |
| * Force the scroller's status to finished (without setting its |
| * position to the end) |
| */ |
| mScroller.forceFinished(true); |
| |
| if (scrollIntoSlots) scrollIntoSlots(); |
| } |
| |
| @Override |
| public void run() { |
| |
| if (mItemCount == 0) { |
| endFling(true); |
| return; |
| } |
| |
| mShouldStopFling = false; |
| |
| final Scroller scroller = mScroller; |
| boolean more = scroller.computeScrollOffset(); |
| final int x = scroller.getCurrX(); |
| |
| // Flip sign to convert finger direction to list items direction |
| // (e.g. finger moving down means list is moving towards the top) |
| int delta = mLastFlingX - x; |
| |
| // Pretend that each frame of a fling scroll is a touch scroll |
| if (delta > 0) { |
| // Moving towards the left. Use leftmost view as mDownTouchPosition |
| mDownTouchPosition = mIsRtl ? (mFirstPosition + getChildCount() - 1) : |
| mFirstPosition; |
| |
| // Don't fling more than 1 screen |
| delta = Math.min(getWidth() - mPaddingLeft - mPaddingRight - 1, delta); |
| } else { |
| // Moving towards the right. Use rightmost view as mDownTouchPosition |
| int offsetToLast = getChildCount() - 1; |
| mDownTouchPosition = mIsRtl ? mFirstPosition : |
| (mFirstPosition + getChildCount() - 1); |
| |
| // Don't fling more than 1 screen |
| delta = Math.max(-(getWidth() - mPaddingRight - mPaddingLeft - 1), delta); |
| } |
| |
| trackMotionScroll(delta); |
| |
| if (more && !mShouldStopFling) { |
| mLastFlingX = x; |
| post(this); |
| } else { |
| endFling(true); |
| } |
| } |
| |
| } |
| |
| /** |
| * Gallery extends LayoutParams to provide a place to hold current |
| * Transformation information along with previous position/transformation |
| * info. |
| */ |
| public static class LayoutParams extends ViewGroup.LayoutParams { |
| public LayoutParams(Context c, AttributeSet attrs) { |
| super(c, attrs); |
| } |
| |
| public LayoutParams(int w, int h) { |
| super(w, h); |
| } |
| |
| public LayoutParams(ViewGroup.LayoutParams source) { |
| super(source); |
| } |
| } |
| } |