На уровне API Android 8-10, то есть от 2.2 до 2.3.3, возможно ли перетаскивать одно представление из одного макета в другое? - PullRequest
0 голосов
/ 07 марта 2012

Я нахожусь в ситуации, когда мне нужно перетащить один View из LinearLayout, который содержит 10-20 видов (все виды в пределах LinearLayout выстроены горизонтально), в RelativeLayout, который, в свою очередь,содержит LinearLayout, упомянутый выше.

Я где-то читал, что View нельзя перетаскивать из одного макета в другой, если так, какой будет лучший обходной путь?

Ответы [ 2 ]

1 голос
/ 07 марта 2012

Насколько я знаю, вы не можете, но вы можете повторно использовать элементы макета (если это то, что вы хотите) http://developer.android.com/resources/articles/layout-tricks-reuse.html

0 голосов
/ 07 марта 2012
//DragController
public class DragController {
    private static final String TAG = "DragController";

    /** Indicates the drag is a move.  */
    public static int DRAG_ACTION_MOVE = 0;

    /** Indicates the drag is a copy.  */
    public static int DRAG_ACTION_COPY = 1;

    private static final int VIBRATE_DURATION = 35;

    private static final boolean PROFILE_DRAWING_DURING_DRAG = false;

    private Context mContext;
    private Vibrator mVibrator;

    // temporaries to avoid gc thrash
    private Rect mRectTemp = new Rect();
    private final int[] mCoordinatesTemp = new int[2];

    /** Whether or not we're dragging. */
    private boolean mDragging;

    /** X coordinate of the down event. */
    private float mMotionDownX;

    /** Y coordinate of the down event. */
    private float mMotionDownY;

    /** Info about the screen for clamping. */
    private DisplayMetrics mDisplayMetrics = new DisplayMetrics();

    /** Original view that is being dragged.  */
    private View mOriginator;

    /** X offset from the upper-left corner of the cell to where we touched.  */
    private float mTouchOffsetX;

    /** Y offset from the upper-left corner of the cell to where we touched.  */
    private float mTouchOffsetY;

    /** Where the drag originated */
    private DragSource mDragSource;

    /** The data associated with the object being dragged */
    private Object mDragInfo;

    /** The view that moves around while you drag.  */
    private DragView mDragView;

    /** Who can receive drop events */
    private ArrayList<DropTarget> mDropTargets = new ArrayList<DropTarget>();

    private DragListener mListener;

    /** The window token used as the parent for the DragView. */
    private IBinder mWindowToken;

    private View mMoveTarget;

    private DropTarget mLastDropTarget;

    private InputMethodManager mInputMethodManager;


    interface DragListener {


        void onDragStart(DragSource source, Object info, int dragAction);

        /**
         * The drag has eneded
         */
        void onDragEnd();
    }

    /**
     * Used to create a new DragLayer from XML.
     *
     * @param context The application's context.
     */
    public DragController(Context context) {
        mContext = context;
        mVibrator = (Vibrator) context.getSystemService(Context.VIBRATOR_SERVICE);

    }


    public void startDrag(View v, DragSource source, Object dragInfo, int dragAction) {
        mOriginator = v;

        Bitmap b = getViewBitmap(v);

        if (b == null) {
            // out of memory?
            return;
        }

        int[] loc = mCoordinatesTemp;
        v.getLocationOnScreen(loc);
        int screenX = loc[0];
        int screenY = loc[1];

        startDrag(b, screenX, screenY, 0, 0, b.getWidth(), b.getHeight(),
                source, dragInfo, dragAction);

        b.recycle();

        if (dragAction == DRAG_ACTION_MOVE) {
            v.setVisibility(View.GONE);
        }
    }


    public void startDrag(Bitmap b, int screenX, int screenY,
            int textureLeft, int textureTop, int textureWidth, int textureHeight,
            DragSource source, Object dragInfo, int dragAction) {
        if (PROFILE_DRAWING_DURING_DRAG) {
            android.os.Debug.startMethodTracing("Launcher");
        }

        // Hide soft keyboard, if visible
        if (mInputMethodManager == null) {
            mInputMethodManager = (InputMethodManager)
                    mContext.getSystemService(Context.INPUT_METHOD_SERVICE);
        }
        mInputMethodManager.hideSoftInputFromWindow(mWindowToken, 0);

        if (mListener != null) {
            mListener.onDragStart(source, dragInfo, dragAction);
        }

        int registrationX = ((int)mMotionDownX) - screenX;
        int registrationY = ((int)mMotionDownY) - screenY;

        mTouchOffsetX = mMotionDownX - screenX;
        mTouchOffsetY = mMotionDownY - screenY;

        mDragging = true;
        mDragSource = source;
        mDragInfo = dragInfo;

        mVibrator.vibrate(VIBRATE_DURATION);
        DragView dragView = mDragView = new DragView(mContext, b, registrationX, registrationY,
                textureLeft, textureTop, textureWidth, textureHeight);
        dragView.show(mWindowToken, (int)mMotionDownX, (int)mMotionDownY);
    }

    /**
     * Draw the view into a bitmap.
     */
    private Bitmap getViewBitmap(View v) {
        v.clearFocus();
        v.setPressed(false);

        boolean willNotCache = v.willNotCacheDrawing();
        v.setWillNotCacheDrawing(false);

        // Reset the drawing cache background color to fully transparent
        // for the duration of this operation
        int color = v.getDrawingCacheBackgroundColor();
        v.setDrawingCacheBackgroundColor(0);

        if (color != 0) {
            v.destroyDrawingCache();
        }
        v.buildDrawingCache();
        Bitmap cacheBitmap = v.getDrawingCache();
        if (cacheBitmap == null) {
            Log.e(TAG, "failed getViewBitmap(" + v + ")", new RuntimeException());
            return null;
        }

        Bitmap bitmap = Bitmap.createBitmap(cacheBitmap);

        // Restore the view
        v.destroyDrawingCache();
        v.setWillNotCacheDrawing(willNotCache);
        v.setDrawingCacheBackgroundColor(color);

        return bitmap;
    }


    public boolean dispatchKeyEvent(KeyEvent event) {
        return mDragging;
    }

    /**
     * Stop dragging without dropping.
     */
    public void cancelDrag() {
        endDrag();
    }

    private void endDrag() {
        if (mDragging) {
            mDragging = false;
            if (mOriginator != null) {
                mOriginator.setVisibility(View.VISIBLE);
            }
            if (mListener != null) {
                mListener.onDragEnd();
            }
            if (mDragView != null) {
                mDragView.remove();
                mDragView = null;
            }
        }
    }

    /**
     * Call this from a drag source view.
     */
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        final int action = ev.getAction();

        if (action == MotionEvent.ACTION_DOWN) {
            recordScreenSize();
        }

        final int screenX = clamp((int)ev.getRawX(), 0, mDisplayMetrics.widthPixels);
        final int screenY = clamp((int)ev.getRawY(), 0, mDisplayMetrics.heightPixels);

        switch (action) {
            case MotionEvent.ACTION_MOVE:
                break;

            case MotionEvent.ACTION_DOWN:
                // Remember location of down touch
                mMotionDownX = screenX;
                mMotionDownY = screenY;
                mLastDropTarget = null;
                break;

            case MotionEvent.ACTION_CANCEL:
            case MotionEvent.ACTION_UP:
                if (mDragging) {
                    drop(screenX, screenY);
                }
                endDrag();
                break;
        }

        return mDragging;
    }

    /**
     * Sets the view that should handle move events.
     */
    void setMoveTarget(View view) {
        mMoveTarget = view;
    }    

    public boolean dispatchUnhandledMove(View focused, int direction) {
        return mMoveTarget != null && mMoveTarget.dispatchUnhandledMove(focused, direction);
    }

    /**
     * Call this from a drag source view.
     */
    public boolean onTouchEvent(MotionEvent ev) {
        if (!mDragging) {
            return false;
        }

        final int action = ev.getAction();
        final int screenX = clamp((int)ev.getRawX(), 0, mDisplayMetrics.widthPixels);
        final int screenY = clamp((int)ev.getRawY(), 0, mDisplayMetrics.heightPixels);

        switch (action) {
        case MotionEvent.ACTION_DOWN:
            // Remember where the motion event started
            mMotionDownX = screenX;
            mMotionDownY = screenY;
            break;
        case MotionEvent.ACTION_MOVE:
            // Update the drag view.  Don't use the clamped pos here so the dragging looks
            // like it goes off screen a little, intead of bumping up against the edge.
            mDragView.move((int)ev.getRawX(), (int)ev.getRawY());
            // Drop on someone?
            final int[] coordinates = mCoordinatesTemp;
            DropTarget dropTarget = findDropTarget(screenX, screenY, coordinates);
            if (dropTarget != null) {
                if (mLastDropTarget == dropTarget) {
                    dropTarget.onDragOver(mDragSource, coordinates[0], coordinates[1],
                        (int) mTouchOffsetX, (int) mTouchOffsetY, mDragView, mDragInfo);
                } else {
                    if (mLastDropTarget != null) {
                        mLastDropTarget.onDragExit(mDragSource, coordinates[0], coordinates[1],
                            (int) mTouchOffsetX, (int) mTouchOffsetY, mDragView, mDragInfo);
                    }
                    dropTarget.onDragEnter(mDragSource, coordinates[0], coordinates[1],
                        (int) mTouchOffsetX, (int) mTouchOffsetY, mDragView, mDragInfo);
                }
            } else {
                if (mLastDropTarget != null) {
                    mLastDropTarget.onDragExit(mDragSource, coordinates[0], coordinates[1],
                        (int) mTouchOffsetX, (int) mTouchOffsetY, mDragView, mDragInfo);
                }
            }
            mLastDropTarget = dropTarget;

            /* The original Launcher activity supports a delete region and scrolling.
               It is not needed in this example.

            // Scroll, maybe, but not if we're in the delete region.
            boolean inDeleteRegion = false;
            if (mDeleteRegion != null) {
                inDeleteRegion = mDeleteRegion.contains(screenX, screenY);
            }
            //Log.d(TAG, "inDeleteRegion=" + inDeleteRegion + " screenX=" + screenX
            //        + " mScrollZone=" + mScrollZone);
            if (!inDeleteRegion && screenX < mScrollZone) {
                if (mScrollState == SCROLL_OUTSIDE_ZONE) {
                    mScrollState = SCROLL_WAITING_IN_ZONE;
                    mScrollRunnable.setDirection(SCROLL_LEFT);
                    mHandler.postDelayed(mScrollRunnable, SCROLL_DELAY);
                }
            } else if (!inDeleteRegion && screenX > scrollView.getWidth() - mScrollZone) {
                if (mScrollState == SCROLL_OUTSIDE_ZONE) {
                    mScrollState = SCROLL_WAITING_IN_ZONE;
                    mScrollRunnable.setDirection(SCROLL_RIGHT);
                    mHandler.postDelayed(mScrollRunnable, SCROLL_DELAY);
                }
            } else {
                if (mScrollState == SCROLL_WAITING_IN_ZONE) {
                    mScrollState = SCROLL_OUTSIDE_ZONE;
                    mScrollRunnable.setDirection(SCROLL_RIGHT);
                    mHandler.removeCallbacks(mScrollRunnable);
                }
            }
            */
            break;
        case MotionEvent.ACTION_UP:
            if (mDragging) {
                drop(screenX, screenY);
            }
            endDrag();

            break;
        case MotionEvent.ACTION_CANCEL:
            cancelDrag();
        }

        return true;
    }

    private boolean drop(float x, float y) {

        final int[] coordinates = mCoordinatesTemp;
        DropTarget dropTarget = findDropTarget((int) x, (int) y, coordinates);

        if (dropTarget != null) {
            dropTarget.onDragExit(mDragSource, coordinates[0], coordinates[1],
                    (int) mTouchOffsetX, (int) mTouchOffsetY, mDragView, mDragInfo);
            if (dropTarget.acceptDrop(mDragSource, coordinates[0], coordinates[1],
                    (int) mTouchOffsetX, (int) mTouchOffsetY, mDragView, mDragInfo)) {
                dropTarget.onDrop(mDragSource, coordinates[0], coordinates[1],
                        (int) mTouchOffsetX, (int) mTouchOffsetY, mDragView, mDragInfo);
                mDragSource.onDropCompleted((View) dropTarget, true);
                return true;
            } else {
                mDragSource.onDropCompleted((View) dropTarget, false);
                return true;
            }
        }
        return false;
    }

    private DropTarget findDropTarget(int x, int y, int[] dropCoordinates) {
        final Rect r = mRectTemp;

        final ArrayList<DropTarget> dropTargets = mDropTargets;
        final int count = dropTargets.size();
        for (int i=count-1; i>=0; i--) {
            final DropTarget target = dropTargets.get(i);
            target.getHitRect(r);
            target.getLocationOnScreen(dropCoordinates);
            r.offset(dropCoordinates[0] - target.getLeft(), dropCoordinates[1] - target.getTop());
            if (r.contains(x, y)) {
                dropCoordinates[0] = x - dropCoordinates[0];
                dropCoordinates[1] = y - dropCoordinates[1];
                return target;
            }
        }
        return null;
    }

    /**
     * Get the screen size so we can clamp events to the screen size so even if
     * you drag off the edge of the screen, we find something.
     */
    private void recordScreenSize() {
        ((WindowManager)mContext.getSystemService(Context.WINDOW_SERVICE))
                .getDefaultDisplay().getMetrics(mDisplayMetrics);
    }

    /**
     * Clamp val to be &gt;= min and &lt; max.
     */
    private static int clamp(int val, int min, int max) {
        if (val < min) {
            return min;
        } else if (val >= max) {
            return max - 1;
        } else {
            return val;
        }
    }

    public void setWindowToken(IBinder token) {
        mWindowToken = token;
    }

    /**
     * Sets the drag listner which will be notified when a drag starts or ends.
     */
    public void setDragListener(DragListener l) {
        mListener = l;
    }

    /**
     * Remove a previously installed drag listener.
     */
    public void removeDragListener(DragListener l) {
        mListener = null;
    }

    /**
     * Add a DropTarget to the list of potential places to receive drop events.
     */
    public void addDropTarget(DropTarget target) {
        mDropTargets.add(target);
    }

    /**
     * Don't send drop events to <em>target</em> any more.
     */
    public void removeDropTarget(DropTarget target) {
        mDropTargets.remove(target);
    }

}




//DragLayer



public class DragLayer extends MyAbsoluteLayout 
    implements DragSource, DropTarget
{
    DragController mDragController;


    public DragLayer (Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public void setDragController(DragController controller) {
        mDragController = controller;
    }

    @Override
    public boolean dispatchKeyEvent(KeyEvent event) {
        return mDragController.dispatchKeyEvent(event) || super.dispatchKeyEvent(event);
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        return mDragController.onInterceptTouchEvent(ev);
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        return mDragController.onTouchEvent(ev);
    }

    @Override
    public boolean dispatchUnhandledMove(View focused, int direction) {
        return mDragController.dispatchUnhandledMove(focused, direction);
    }



public void onDropCompleted (View target, boolean success)
{
    toast ("DragLayer2.onDropCompleted: " + target.getId () + " Check that the view moved.");
}


public void onDrop(DragSource source, int x, int y, int xOffset, int yOffset,
        DragView dragView, Object dragInfo)
{
    View v = (View) dragInfo;
    toast ("DragLayer2.onDrop accepts view: " + v.getId ()
          + "x, y, xO, yO :" + new Integer (x) + ", " + new Integer (y) + ", "
          + new Integer (xOffset) + ", " + new Integer (yOffset));

    int w = v.getWidth ();
    int h = v.getHeight ();
    int left = x - xOffset;
    int top = y - yOffset;
    DragLayer.LayoutParams lp = new DragLayer.LayoutParams (w, h, left, top);
    this.updateViewLayout(v, lp);
}

public void onDragEnter(DragSource source, int x, int y, int xOffset, int yOffset,
        DragView dragView, Object dragInfo)
{
}

public void onDragOver(DragSource source, int x, int y, int xOffset, int yOffset,
        DragView dragView, Object dragInfo)
{
}

public void onDragExit(DragSource source, int x, int y, int xOffset, int yOffset,
        DragView dragView, Object dragInfo)
{
}


public boolean acceptDrop(DragSource source, int x, int y, int xOffset, int yOffset,
        DragView dragView, Object dragInfo)
{
    return true;
}


public Rect estimateDropLocation(DragSource source, int x, int y, int xOffset, int yOffset,
            DragView dragView, Object dragInfo, Rect recycle)
{
    return null;
}

public void toast (String msg)
{
    if (!Dashboard.Debugging) return;
    Toast.makeText (getContext (), msg, Toast.LENGTH_SHORT).show ();
} // end toast


} // end class


//DragSource

public interface DragSource {
    void setDragController(DragController dragger);
    void onDropCompleted(View target, boolean success);
}


//DragView


public class DragView extends View 
{
    // Number of pixels to add to the dragged item for scaling.  Should be even for pixel alignment.
    private static final int DRAG_SCALE = 0;   // In Launcher, value is 40

    private Bitmap mBitmap;
    private Paint mPaint;
    private int mRegistrationX;
    private int mRegistrationY;

    private float mScale;
    private float mAnimationScale = 1.0f;

    private WindowManager.LayoutParams mLayoutParams;
    private WindowManager mWindowManager;


    public DragView(Context context, Bitmap bitmap, int registrationX, int registrationY,
            int left, int top, int width, int height) {
        super(context);

        // mWindowManager = WindowManagerImpl.getDefault();
        mWindowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);        

        Matrix scale = new Matrix();
        float scaleFactor = width;
        scaleFactor = mScale = (scaleFactor + DRAG_SCALE) / scaleFactor;
        scale.setScale(scaleFactor, scaleFactor);
        mBitmap = Bitmap.createBitmap(bitmap, left, top, width, height, scale, true);

        // The point in our scaled bitmap that the touch events are located
        mRegistrationX = registrationX + (DRAG_SCALE / 2);
        mRegistrationY = registrationY + (DRAG_SCALE / 2);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        setMeasuredDimension(mBitmap.getWidth(), mBitmap.getHeight());
    }

    @Override
    protected void onDraw(Canvas canvas) {
        if (true) {
            // for debugging
            Paint p = new Paint();
            p.setStyle(Paint.Style.FILL);
            p.setColor(0x88dd0011);
            canvas.drawRect(0, 0, getWidth(), getHeight(), p);
        }
        float scale = mAnimationScale;
        if (scale < 0.999f) { // allow for some float error
            float width = mBitmap.getWidth();
            float offset = (width-(width*scale))/2;
            canvas.translate(offset, offset);
            canvas.scale(scale, scale);
        }
        canvas.drawBitmap(mBitmap, 0.0f, 0.0f, mPaint);
    }

    @Override
    protected void onDetachedFromWindow() {
        super.onDetachedFromWindow();
        mBitmap.recycle();
    }

    public void setPaint(Paint paint) {
        mPaint = paint;
        invalidate();
    }

    public void show(IBinder windowToken, int touchX, int touchY) {
        WindowManager.LayoutParams lp;
        int pixelFormat;

        pixelFormat = PixelFormat.TRANSLUCENT;

        lp = new WindowManager.LayoutParams(
                ViewGroup.LayoutParams.WRAP_CONTENT,
                ViewGroup.LayoutParams.WRAP_CONTENT,
                touchX-mRegistrationX, touchY-mRegistrationY,
                WindowManager.LayoutParams.TYPE_APPLICATION_SUB_PANEL,
                WindowManager.LayoutParams.FLAG_LAYOUT_IN_SCREEN
                    | WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS
                    /*| WindowManager.LayoutParams.FLAG_ALT_FOCUSABLE_IM*/,
                pixelFormat);
//        lp.token = mStatusBarView.getWindowToken();
        lp.gravity = Gravity.LEFT | Gravity.TOP;
        lp.token = windowToken;
        lp.setTitle("DragView");
        mLayoutParams = lp;

        mWindowManager.addView(this, lp);

    }

    void move(int touchX, int touchY) {
        // This is what was done in the Launcher code.
        WindowManager.LayoutParams lp = mLayoutParams;
        lp.x = touchX - mRegistrationX;
        lp.y = touchY - mRegistrationY;
        mWindowManager.updateViewLayout(this, lp);
    }

    void remove() {
        mWindowManager.removeView(this);
    }
}


//MainActivity

private DragController mDragController;
    private DragLayer mDragLayer;

//onCreate
mDragController = new DragController(this);

        DragController dragController = mDragController;

        mDragLayer = (DragLayer) findViewById(R.id.drag_layer);
        mDragLayer.setDragController(dragController);
        dragController.addDropTarget(mDragLayer);
RelativeLayout img1=new RelativeLayout(this);
        DragLayer.LayoutParams lp1 = new DragLayer.LayoutParams(100, 100, 15,
                15);
        img1.setLayoutParams(lp1);

img1.setOnLongClickListener(this);




public boolean onLongClick(View v) {
        trace("onLongClick in view: " + v);

        // Make sure the drag was started by a long press as opposed to a long
        // click.
        // (Note: I got this from the Workspace object in the Android Launcher
        // code.
        // I think it is here to ensure that the device is still in touch mode
        // as we start the drag operation.)
        if (!v.isInTouchMode()) {
            toast("isInTouchMode returned false. Try touching the view again.");
            return false;
        }
        return startDrag(v);
    }
//function
public boolean startDrag(View v) {
        // Let the DragController initiate a drag-drop sequence.
        // I use the dragInfo to pass along the object being dragged.
        // I'm not sure how the Launcher designers do this.
        Object dragInfo = v;
        mDragController.startDrag(v, mDragLayer, dragInfo,
                DragController.DRAG_ACTION_MOVE);
        return true;
    }
...