android.view.DragEvent#getX ( )源码实例Demo

@Override
public boolean onDragEvent(DragEvent event) {
    if (event.getAction() == DragEvent.ACTION_DRAG_LOCATION) {
        Point p = new Point((int) event.getX(), (int) event.getY());
        if (!roaming) {
            roaming = true;
            points.add(p);
        } else {
            try {
                points.set(points.size() - 1, p);
            } catch (Exception e) {
                Reset();
                FileLog.e("Yahala", e);
            }
        }
        invalidate();
    }
    return true;
}
 

/**
 * 获取拖拽触发的执行事件类型
 *
 * @param draggedViewPager 最外层 {@link com.bigfat.draggedviewpager.view.MDA_DraggedViewPager}
 * @param currentPageIndex 当前页索引
 * @param pageIndex        响应拖拽事件item所在页索引
 * @param view             响应拖拽事件的item
 * @param event            拖拽事件
 * @return 拖拽事件类型
 */
public static DragEventType getDragEventType(MDA_DraggedViewPager draggedViewPager, int currentPageIndex, int pageIndex,
    View view, DragEvent event) {
    if (currentPageIndex > 0//有上一页
        && (draggedViewPager.getPageDragSetting() == null || draggedViewPager.getPageDragSetting()
        .canBeSwiped(currentPageIndex - 1))//上一页可被交换
        //触摸至上一页//或至触摸至当前页左边界，则切换到上一页
        && (pageIndex < currentPageIndex || (pageIndex == currentPageIndex && event.getX() < view.getWidth() / 8))) {
        return DragEventType.SCROLL_PREVIOUS;
    } else if (currentPageIndex < (draggedViewPager.getContainer().getChildCount() - 1)//在有下一页的前提下
        && (draggedViewPager.getPageDragSetting() == null || draggedViewPager.getPageDragSetting()
        .canBeSwiped(currentPageIndex + 1))//下一页可被交换
        //触摸至下一页//或至触摸至当前页右边界，则切换到下一页
        && (pageIndex > currentPageIndex || (pageIndex == currentPageIndex && event.getX() > view.getWidth() / 8 * 7))) {
        return DragEventType.SCROLL_NEXT;
    }
    return DragEventType.DEFAULT;
}
 

/**
 * 计算控件位置
 */
private void compute(int type, Rect rect, DragEvent event){

    int size = mPhoneContentWidth / WIDTH_COUNT - dp2px(10);
    int x = (int) event.getX();
    int y = (int) event.getY();

    if (type == ONE_BY_ONE_PIC || type == ONE_BY_ONE_TEXT){
        // 1 * 1 方格
        rect.left = x - size / 2;
        rect.top = y - size / 2;
        rect.right = x + size / 2;
        rect.bottom = y + size / 2;
    }else if (type == THREE_BY_THREE_PIC){
        // 3 * 3 方格
        rect.left = x - size * 3 / 2;
        rect.top = y - size * 3 / 2;
        rect.right = x + size * 3 / 2;
        rect.bottom = y + size * 3 / 2;
    }else if (type == ONE_BY_TWO_PIC){
        // 1 * 2 方格
        rect.left = x - size / 2;
        rect.top = y - size;
        rect.right = x + size / 2;
        rect.bottom = y + size;
    }
}
 

@Override
public boolean onDragEvent (DragEvent event) {
    final int action = event.getAction();

    switch (action) {
        case DragEvent.ACTION_DRAG_STARTED:
            mLastX = event.getX();
            mLastY = event.getY();
            return true;

        case DragEvent.ACTION_DRAG_ENTERED:
            return true;

        case DragEvent.ACTION_DRAG_LOCATION:
            mLastX = event.getX();
            mLastY = event.getY();
            mEventListener.onDriverDragMove(event.getX(), event.getY());
            return true;

        case DragEvent.ACTION_DROP:
            mLastX = event.getX();
            mLastY = event.getY();
            mEventListener.onDriverDragMove(event.getX(), event.getY());
            mEventListener.onDriverDragEnd(mLastX, mLastY);
            return true;
        case DragEvent.ACTION_DRAG_EXITED:
            mEventListener.onDriverDragExitWindow();
            return true;

        case DragEvent.ACTION_DRAG_ENDED:
            mEventListener.onDriverDragCancel();
            return true;

        default:
            return false;
    }
}
 

private void hscrollOnDrag(View view, DragEvent event, HorizontalScrollView scrollView) {
    float tx = view.getLeft() + event.getX();

    if (isAncestor(scrollView, view)) {

        int thresh = scrollView.getWidth() / 6;

        if (tx < scrollView.getScrollX() + thresh) {
            scrollView.smoothScrollBy(-10, 0);
        } else if (tx > scrollView.getScrollX() + scrollView.getWidth() - thresh) {
            scrollView.smoothScrollBy(10,0);
        }
    }
}
 

/**
 * 调整控件位置
 */
private void adjust(int type, Rect rect, DragEvent event){
    // 最小单元格宽高
    int size = mPhoneContentWidth / WIDTH_COUNT / 2;
    // 手机屏幕间距
    int padding = dp2px(5);
    // 1 * 1方格宽高
    int width = size * 2 - dp2px(10);

    int offsetX = (rect.left - padding) % size;
    if (offsetX < size / 2){
        rect.left = rect.left + padding - offsetX;
    }else {
        rect.left = rect.left + padding - offsetX + size;
    }

    int offsetY = (rect.top - padding) % size;
    if (offsetY < size / 2){
        rect.top = rect.top + padding - offsetY;
    }else {
        rect.top = rect.top + padding - offsetY + size;
    }
    
    if (type == ONE_BY_ONE_PIC || type == ONE_BY_ONE_TEXT){
        rect.right = rect.left + width;
        rect.bottom = rect.top + width;
        
    }else if (type == ONE_BY_TWO_PIC){
        rect.top = rect.top + padding;
        rect.right = rect.left + width;
        rect.bottom = rect.top + width * 2;
    }else if (type == THREE_BY_THREE_PIC){
        rect.top = rect.top + padding * 2;
        rect.left = rect.left + padding * 2;
        rect.right = rect.left + width * 3;
        rect.bottom = rect.top + width * 3;
    }

    //超出部分修正(超出部分)
    if (rect.right > frameLayout.getWidth() || rect.bottom > frameLayout.getHeight()){

        int currentX = (int) event.getX();
        int currentY = (int) event.getY();

        int centerX = frameLayout.getWidth() / 2;
        int centerY = frameLayout.getHeight() / 2;

        if (currentX <= centerX && currentY <= centerY){
            //左上角区域

        }else if (currentX >= centerX && currentY <= centerY){
            //右上角区域
            rect.left = rect.left - size;
            rect.right = rect.right - size;
        }else if (currentX <= centerX && currentY >= centerY){
            //左下角区域
            rect.top = rect.top - size;
            rect.bottom = rect.bottom - size;
        }else if (currentX >= centerX && currentY >= centerY){
            //右下角区域
            if (rect.right > frameLayout.getWidth()){
                rect.left = rect.left - size;
                rect.right = rect.right - size;
            }
            if (rect.bottom > frameLayout.getHeight()){
                rect.top = rect.top - size;
                rect.bottom = rect.bottom - size;
            }
        }
    }
}
 

private boolean onDragStart(DragEvent event) {
    if (!mRequest.isValid()) {
        return false;
    }
    ClipDescription desc =  event.getClipDescription();
    if (desc == null || !desc.hasMimeType(getMimeType())) {
        return false;
    }

    final PendingAddItemInfo item;
    if (mRequest.getRequestType() == PinItemRequestCompat.REQUEST_TYPE_SHORTCUT) {
        item = new PendingAddShortcutInfo(
                new PinShortcutRequestActivityInfo(mRequest, mLauncher));
    } else {
        // mRequest.getRequestType() == PinItemRequestCompat.REQUEST_TYPE_APPWIDGET
        LauncherAppWidgetProviderInfo providerInfo =
                LauncherAppWidgetProviderInfo.fromProviderInfo(
                        mLauncher, mRequest.getAppWidgetProviderInfo(mLauncher));
        final PinWidgetFlowHandler flowHandler =
                new PinWidgetFlowHandler(providerInfo, mRequest);
        item = new PendingAddWidgetInfo(providerInfo) {
            @Override
            public WidgetAddFlowHandler getHandler() {
                return flowHandler;
            }
        };
    }
    View view = new View(mLauncher);
    view.setTag(item);

    Point downPos = new Point((int) event.getX(), (int) event.getY());
    DragOptions options = new DragOptions();
    options.systemDndStartPoint = downPos;
    options.preDragCondition = this;

    // We use drag event position as the screenPos for the preview image. Since mPreviewRect
    // already includes the view position relative to the drag event on the source window,
    // and the absolute position (position relative to the screen) of drag event is same
    // across windows, using drag position here give a good estimate for relative position
    // to source window.
    PendingItemDragHelper dragHelper = new PendingItemDragHelper(view);
    if (mRequest.getRequestType() == PinItemRequestCompat.REQUEST_TYPE_APPWIDGET) {
        dragHelper.setPreview(getPreview(mRequest));
    }

    dragHelper.startDrag(new Rect(mPreviewRect),
            mPreviewBitmapWidth, mPreviewViewWidth, downPos,  this, options);
    mDragStartTime = SystemClock.uptimeMillis();
    return true;
}
 

/**
     * @param v     View
     * @param event DragEvent
     * @return boolean
     */
    @Override
    public boolean onDrag(final View v, final DragEvent event)
    {
        if (v instanceof PipeView)
        {
            final PipeView pipeView = (PipeView) v;
            switch (event.getAction())
            {
                case DragEvent.ACTION_DRAG_STARTED:
                {
                    //init values
                    xCoord = 0;
                    yCoord = 0;
                    dropped = false;
                    createRecycleBin(pipeView);
                    break;
                }
                case DragEvent.ACTION_DRAG_ENTERED:
                    break;
                case DragEvent.ACTION_DRAG_EXITED:
                    break;
                case DragEvent.ACTION_DROP:
                    //update drop location
                    xCoord = event.getX();
                    yCoord = event.getY();
                    dropped = true;
                    ComponentView view = (ComponentView) event.getLocalState();
                    pipeView.getGrid().setGridValue(view.getGridX(), view.getGridY(), false);
                    break;
                case DragEvent.ACTION_DRAG_ENDED:
                    cleanup(pipeView, event);
                    break;
                case DragEvent.ACTION_DRAG_LOCATION:
                {
//                    //@todo add scroll behaviour to drag and drop
//                    HorizontalScrollView horizontalScrollView = (HorizontalScrollView) pipeView.getParent();
//                    if (horizontalScrollView != null)
//                    {
//                        ScrollView scrollView = (ScrollView) horizontalScrollView.getParent();
//                        if (scrollView != null)
//                        {
//                            //way one
//                            int y = Math.round(event.getY());
//                            int translatedY = y - scrollView.getScrollY();
//                            int threshold = 50;
//                            // make a scrolling up due the y has passed the threshold
//                            if (translatedY < threshold) {
//                                // make a scroll up by 30 px
//                                scrollView.smoothScrollBy(0, -30);
//                            }
//                            // make a autoscrolling down due y has passed the 500 px border
//                            if (translatedY + threshold > 500) {
//                                // make a scroll down by 30 px
//                                scrollView.smoothScrollBy(0, 30);
//                            }
//                            //way two
//                            int topOfDropZone = pipeView.getTop();
//                            int bottomOfDropZone = pipeView.getBottom();
//                            int scrollY = scrollView.getScrollY();
//                            int scrollViewHeight = scrollView.getMeasuredHeight();
//                            Log.d("location: Scroll Y: " + scrollY + " Scroll Y+Height: " + (scrollY + scrollViewHeight));
//                            Log.d(" top: " + topOfDropZone + " bottom: " + bottomOfDropZone);
//                            if (bottomOfDropZone > (scrollY + scrollViewHeight - 100))
//                            {
//                                scrollView.smoothScrollBy(0, 30);
//                            }
//                            if (topOfDropZone < (scrollY + 100))
//                            {
//                                scrollView.smoothScrollBy(0, -30);
//                            }
//                        }
//                    }
                    break;
                }
                default:
                    break;
            }
            return true;
        }
        return false;
    }
 

/**
 * @see View#onDragEvent(DragEvent)
 */
@TargetApi(Build.VERSION_CODES.N)
public boolean onDragEvent(DragEvent event) {
    if (mNativeContentViewCore == 0 || Build.VERSION.SDK_INT <= Build.VERSION_CODES.M) {
        return false;
    }

    ClipDescription clipDescription = event.getClipDescription();

    // text/* will match text/uri-list, text/html, text/plain.
    String[] mimeTypes =
            clipDescription == null ? new String[0] : clipDescription.filterMimeTypes("text/*");

    if (event.getAction() == DragEvent.ACTION_DRAG_STARTED) {
        // TODO(hush): support dragging more than just text.
        return mimeTypes != null && mimeTypes.length > 0
                && nativeIsTouchDragDropEnabled(mNativeContentViewCore);
    }

    StringBuilder content = new StringBuilder("");
    if (event.getAction() == DragEvent.ACTION_DROP) {
        // TODO(hush): obtain dragdrop permissions, when dragging files into Chrome/WebView is
        // supported. Not necessary to do so for now, because only text dragging is supported.
        ClipData clipData = event.getClipData();
        final int itemCount = clipData.getItemCount();
        for (int i = 0; i < itemCount; i++) {
            ClipData.Item item = clipData.getItemAt(i);
            content.append(item.coerceToStyledText(mContainerView.getContext()));
        }
    }

    int[] locationOnScreen = new int[2];
    mContainerView.getLocationOnScreen(locationOnScreen);

    float xPix = event.getX() + mCurrentTouchOffsetX;
    float yPix = event.getY() + mCurrentTouchOffsetY;

    int xCss = (int) mRenderCoordinates.fromPixToDip(xPix);
    int yCss = (int) mRenderCoordinates.fromPixToDip(yPix);
    int screenXCss = (int) mRenderCoordinates.fromPixToDip(xPix + locationOnScreen[0]);
    int screenYCss = (int) mRenderCoordinates.fromPixToDip(yPix + locationOnScreen[1]);

    nativeOnDragEvent(mNativeContentViewCore, event.getAction(), xCss, yCss, screenXCss,
            screenYCss, mimeTypes, content.toString());
    return true;
}