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Diffstat (limited to 'src/com/android/launcher3/PagedViewWithDraggableItems.java')
| -rw-r--r-- | src/com/android/launcher3/PagedViewWithDraggableItems.java | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/src/com/android/launcher3/PagedViewWithDraggableItems.java b/src/com/android/launcher3/PagedViewWithDraggableItems.java new file mode 100644 index 000000000..8f10ecfa5 --- /dev/null +++ b/src/com/android/launcher3/PagedViewWithDraggableItems.java @@ -0,0 +1,178 @@ +/* + * Copyright (C) 2010 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 com.android.launcher3; + +import android.content.Context; +import android.util.AttributeSet; +import android.view.MotionEvent; +import android.view.View; + + +/* Class that does most of the work of enabling dragging items out of a PagedView by performing a + * vertical drag. Used by both CustomizePagedView and AllAppsPagedView. + * Subclasses must do the following: + * * call setDragSlopeThreshold after making an instance of the PagedViewWithDraggableItems + * * call child.setOnLongClickListener(this) and child.setOnTouchListener(this) on all children + * (good place to do it is in syncPageItems) + * * override beginDragging(View) (but be careful to call super.beginDragging(View) + * + */ +public abstract class PagedViewWithDraggableItems extends PagedView + implements View.OnLongClickListener, View.OnTouchListener { + private View mLastTouchedItem; + private boolean mIsDragging; + private boolean mIsDragEnabled; + private float mDragSlopeThreshold; + private Launcher mLauncher; + + public PagedViewWithDraggableItems(Context context) { + this(context, null); + } + + public PagedViewWithDraggableItems(Context context, AttributeSet attrs) { + this(context, attrs, 0); + } + + public PagedViewWithDraggableItems(Context context, AttributeSet attrs, int defStyle) { + super(context, attrs, defStyle); + mLauncher = (Launcher) context; + } + + protected boolean beginDragging(View v) { + boolean wasDragging = mIsDragging; + mIsDragging = true; + return !wasDragging; + } + + protected void cancelDragging() { + mIsDragging = false; + mLastTouchedItem = null; + mIsDragEnabled = false; + } + + private void handleTouchEvent(MotionEvent ev) { + final int action = ev.getAction(); + switch (action & MotionEvent.ACTION_MASK) { + case MotionEvent.ACTION_DOWN: + cancelDragging(); + mIsDragEnabled = true; + break; + case MotionEvent.ACTION_MOVE: + if (mTouchState != TOUCH_STATE_SCROLLING && !mIsDragging && mIsDragEnabled) { + determineDraggingStart(ev); + } + break; + } + } + + @Override + public boolean onInterceptTouchEvent(MotionEvent ev) { + handleTouchEvent(ev); + return super.onInterceptTouchEvent(ev); + } + + @Override + public boolean onTouchEvent(MotionEvent ev) { + handleTouchEvent(ev); + return super.onTouchEvent(ev); + } + + @Override + public boolean onTouch(View v, MotionEvent event) { + mLastTouchedItem = v; + mIsDragEnabled = true; + return false; + } + + @Override + public boolean onLongClick(View v) { + // Return early if this is not initiated from a touch + if (!v.isInTouchMode()) return false; + // Return early if we are still animating the pages + if (mNextPage != INVALID_PAGE) return false; + // When we have exited all apps or are in transition, disregard long clicks + if (!mLauncher.isAllAppsVisible() || + mLauncher.getWorkspace().isSwitchingState()) return false; + // Return if global dragging is not enabled + if (!mLauncher.isDraggingEnabled()) return false; + + return beginDragging(v); + } + + /* + * Determines if we should change the touch state to start scrolling after the + * user moves their touch point too far. + */ + protected void determineScrollingStart(MotionEvent ev) { + if (!mIsDragging) super.determineScrollingStart(ev); + } + + /* + * Determines if we should change the touch state to start dragging after the + * user moves their touch point far enough. + */ + protected void determineDraggingStart(MotionEvent ev) { + /* + * Locally do absolute value. mLastMotionX is set to the y value + * of the down event. + */ + final int pointerIndex = ev.findPointerIndex(mActivePointerId); + final float x = ev.getX(pointerIndex); + final float y = ev.getY(pointerIndex); + final int xDiff = (int) Math.abs(x - mLastMotionX); + final int yDiff = (int) Math.abs(y - mLastMotionY); + + final int touchSlop = mTouchSlop; + boolean yMoved = yDiff > touchSlop; + boolean isUpwardMotion = (yDiff / (float) xDiff) > mDragSlopeThreshold; + + if (isUpwardMotion && yMoved && mLastTouchedItem != null) { + // Drag if the user moved far enough along the Y axis + beginDragging(mLastTouchedItem); + + // Cancel any pending long press + if (mAllowLongPress) { + mAllowLongPress = false; + // Try canceling the long press. It could also have been scheduled + // by a distant descendant, so use the mAllowLongPress flag to block + // everything + final View currentPage = getPageAt(mCurrentPage); + if (currentPage != null) { + currentPage.cancelLongPress(); + } + } + } + } + + public void setDragSlopeThreshold(float dragSlopeThreshold) { + mDragSlopeThreshold = dragSlopeThreshold; + } + + @Override + protected void onDetachedFromWindow() { + cancelDragging(); + super.onDetachedFromWindow(); + } + + /** Show the scrolling indicators when we move the page */ + protected void onPageBeginMoving() { + showScrollingIndicator(false); + } + protected void onPageEndMoving() { + hideScrollingIndicator(false); + } +} |