src/com/android/launcher2/DragView.java - platform/packages/apps/Launcher2 - Git at Google

 /*
  * Copyright (C) 2008 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.launcher2;

 import android.animation.ValueAnimator;
 import android.animation.ValueAnimator.AnimatorUpdateListener;
 import android.content.res.Resources;
 import android.graphics.Bitmap;
 import android.graphics.Canvas;
 import android.graphics.Paint;
 import android.graphics.Point;
 import android.graphics.PorterDuff;
 import android.graphics.PorterDuffColorFilter;
 import android.graphics.Rect;
 import android.view.View;
 import android.view.animation.DecelerateInterpolator;

 import com.android.launcher.R;

 public class DragView extends View {
     private static float sDragAlpha = 1f;

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

     private Point mDragVisualizeOffset = null;
     private Rect mDragRegion = null;
     private DragLayer mDragLayer = null;
     private boolean mHasDrawn = false;
     private float mCrossFadeProgress = 0f;

     ValueAnimator mAnim;
     private float mOffsetX = 0.0f;
     private float mOffsetY = 0.0f;
     private float mInitialScale = 1f;

     /**
      * Construct the drag view.
      * <p>
      * The registration point is the point inside our view that the touch events should
      * be centered upon.
      *
      * @param launcher The Launcher instance
      * @param bitmap The view that we're dragging around.  We scale it up when we draw it.
      * @param registrationX The x coordinate of the registration point.
      * @param registrationY The y coordinate of the registration point.
      */
     public DragView(Launcher launcher, Bitmap bitmap, int registrationX, int registrationY,
             int left, int top, int width, int height, final float initialScale) {
         super(launcher);
         mDragLayer = launcher.getDragLayer();
         mInitialScale = initialScale;

         final Resources res = getResources();
         final float offsetX = res.getDimensionPixelSize(R.dimen.dragViewOffsetX);
         final float offsetY = res.getDimensionPixelSize(R.dimen.dragViewOffsetY);
         final float scaleDps = res.getDimensionPixelSize(R.dimen.dragViewScale);
         final float scale = (width + scaleDps) / width;

         // Set the initial scale to avoid any jumps
         setScaleX(initialScale);
         setScaleY(initialScale);

         // Animate the view into the correct position
         mAnim = LauncherAnimUtils.ofFloat(this, 0f, 1f);
         mAnim.setDuration(150);
         mAnim.addUpdateListener(new AnimatorUpdateListener() {
             @Override
             public void onAnimationUpdate(ValueAnimator animation) {
                 final float value = (Float) animation.getAnimatedValue();

                 final int deltaX = (int) ((value * offsetX) - mOffsetX);
                 final int deltaY = (int) ((value * offsetY) - mOffsetY);

                 mOffsetX += deltaX;
                 mOffsetY += deltaY;
                 setScaleX(initialScale + (value * (scale - initialScale)));
                 setScaleY(initialScale + (value * (scale - initialScale)));
                 if (sDragAlpha != 1f) {
                     setAlpha(sDragAlpha * value + (1f - value));
                 }

                 if (getParent() == null) {
                     animation.cancel();
                 } else {
                     setTranslationX(getTranslationX() + deltaX);
                     setTranslationY(getTranslationY() + deltaY);
                 }
             }
         });

         mBitmap = Bitmap.createBitmap(bitmap, left, top, width, height);
         setDragRegion(new Rect(0, 0, width, height));

         // The point in our scaled bitmap that the touch events are located
         mRegistrationX = registrationX;
         mRegistrationY = registrationY;

         // Force a measure, because Workspace uses getMeasuredHeight() before the layout pass
         int ms = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
         measure(ms, ms);
         mPaint = new Paint(Paint.FILTER_BITMAP_FLAG);
     }

     public float getOffsetY() {
         return mOffsetY;
     }

     public int getDragRegionLeft() {
         return mDragRegion.left;
     }

     public int getDragRegionTop() {
         return mDragRegion.top;
     }

     public int getDragRegionWidth() {
         return mDragRegion.width();
     }

     public int getDragRegionHeight() {
         return mDragRegion.height();
     }

     public void setDragVisualizeOffset(Point p) {
         mDragVisualizeOffset = p;
     }

     public Point getDragVisualizeOffset() {
         return mDragVisualizeOffset;
     }

     public void setDragRegion(Rect r) {
         mDragRegion = r;
     }

     public Rect getDragRegion() {
         return mDragRegion;
     }

     public float getInitialScale() {
         return mInitialScale;
     }

     public void updateInitialScaleToCurrentScale() {
         mInitialScale = getScaleX();
     }

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

     @Override
     protected void onDraw(Canvas canvas) {
         @SuppressWarnings("all") // suppress dead code warning
         final boolean debug = false;
         if (debug) {
             Paint p = new Paint();
             p.setStyle(Paint.Style.FILL);
             p.setColor(0x66ffffff);
             canvas.drawRect(0, 0, getWidth(), getHeight(), p);
         }

         mHasDrawn = true;
         boolean crossFade = mCrossFadeProgress > 0 && mCrossFadeBitmap != null;
         if (crossFade) {
             int alpha = crossFade ? (int) (255 * (1 - mCrossFadeProgress)) : 255;
             mPaint.setAlpha(alpha);
         }
         canvas.drawBitmap(mBitmap, 0.0f, 0.0f, mPaint);
         if (crossFade) {
             mPaint.setAlpha((int) (255 * mCrossFadeProgress));
             canvas.save();
             float sX = (mBitmap.getWidth() * 1.0f) / mCrossFadeBitmap.getWidth();
             float sY = (mBitmap.getHeight() * 1.0f) / mCrossFadeBitmap.getHeight();
             canvas.scale(sX, sY);
             canvas.drawBitmap(mCrossFadeBitmap, 0.0f, 0.0f, mPaint);
             canvas.restore();
         }
     }

     public void setCrossFadeBitmap(Bitmap crossFadeBitmap) {
         mCrossFadeBitmap = crossFadeBitmap;
     }

     public void crossFade(int duration) {
         ValueAnimator va = LauncherAnimUtils.ofFloat(this, 0f, 1f);
         va.setDuration(duration);
         va.setInterpolator(new DecelerateInterpolator(1.5f));
         va.addUpdateListener(new AnimatorUpdateListener() {
             @Override
             public void onAnimationUpdate(ValueAnimator animation) {
                 mCrossFadeProgress = animation.getAnimatedFraction();
             }
         });
         va.start();
     }

     public void setColor(int color) {
         if (mPaint == null) {
             mPaint = new Paint(Paint.FILTER_BITMAP_FLAG);
         }
         if (color != 0) {
             mPaint.setColorFilter(new PorterDuffColorFilter(color, PorterDuff.Mode.SRC_ATOP));
         } else {
             mPaint.setColorFilter(null);
         }
         invalidate();
     }

     public boolean hasDrawn() {
         return mHasDrawn;
     }

     @Override
     public void setAlpha(float alpha) {
         super.setAlpha(alpha);
         mPaint.setAlpha((int) (255 * alpha));
         invalidate();
     }

     /**
      * Create a window containing this view and show it.
      *
      * @param windowToken obtained from v.getWindowToken() from one of your views
      * @param touchX the x coordinate the user touched in DragLayer coordinates
      * @param touchY the y coordinate the user touched in DragLayer coordinates
      */
     public void show(int touchX, int touchY) {
         mDragLayer.addView(this);

         // Start the pick-up animation
         DragLayer.LayoutParams lp = new DragLayer.LayoutParams(0, 0);
         lp.width = mBitmap.getWidth();
         lp.height = mBitmap.getHeight();
         lp.customPosition = true;
         setLayoutParams(lp);
         setTranslationX(touchX - mRegistrationX);
         setTranslationY(touchY - mRegistrationY);
         // Post the animation to skip other expensive work happening on the first frame
         post(new Runnable() {
                 public void run() {
                     mAnim.start();
                 }
             });
     }

     public void cancelAnimation() {
         if (mAnim != null && mAnim.isRunning()) {
             mAnim.cancel();
         }
     }

     public void resetLayoutParams() {
         mOffsetX = mOffsetY = 0;
         requestLayout();
     }

     /**
      * Move the window containing this view.
      *
      * @param touchX the x coordinate the user touched in DragLayer coordinates
      * @param touchY the y coordinate the user touched in DragLayer coordinates
      */
     void move(int touchX, int touchY) {
         setTranslationX(touchX - mRegistrationX + (int) mOffsetX);
         setTranslationY(touchY - mRegistrationY + (int) mOffsetY);
     }

     void remove() {
         if (getParent() != null) {
             mDragLayer.removeView(DragView.this);
         }
     }
 }
	/*
	* Copyright (C) 2008 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.launcher2;

	import android.animation.ValueAnimator;
	import android.animation.ValueAnimator.AnimatorUpdateListener;
	import android.content.res.Resources;
	import android.graphics.Bitmap;
	import android.graphics.Canvas;
	import android.graphics.Paint;
	import android.graphics.Point;
	import android.graphics.PorterDuff;
	import android.graphics.PorterDuffColorFilter;
	import android.graphics.Rect;
	import android.view.View;
	import android.view.animation.DecelerateInterpolator;

	import com.android.launcher.R;

	public class DragView extends View {
	private static float sDragAlpha = 1f;

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

	private Point mDragVisualizeOffset = null;
	private Rect mDragRegion = null;
	private DragLayer mDragLayer = null;
	private boolean mHasDrawn = false;
	private float mCrossFadeProgress = 0f;

	ValueAnimator mAnim;
	private float mOffsetX = 0.0f;
	private float mOffsetY = 0.0f;
	private float mInitialScale = 1f;

	/**
	* Construct the drag view.
	* <p>
	* The registration point is the point inside our view that the touch events should
	* be centered upon.
	*
	* @param launcher The Launcher instance
	* @param bitmap The view that we're dragging around. We scale it up when we draw it.
	* @param registrationX The x coordinate of the registration point.
	* @param registrationY The y coordinate of the registration point.
	*/
	public DragView(Launcher launcher, Bitmap bitmap, int registrationX, int registrationY,
	int left, int top, int width, int height, final float initialScale) {
	super(launcher);
	mDragLayer = launcher.getDragLayer();
	mInitialScale = initialScale;

	final Resources res = getResources();
	final float offsetX = res.getDimensionPixelSize(R.dimen.dragViewOffsetX);
	final float offsetY = res.getDimensionPixelSize(R.dimen.dragViewOffsetY);
	final float scaleDps = res.getDimensionPixelSize(R.dimen.dragViewScale);
	final float scale = (width + scaleDps) / width;

	// Set the initial scale to avoid any jumps
	setScaleX(initialScale);
	setScaleY(initialScale);

	// Animate the view into the correct position
	mAnim = LauncherAnimUtils.ofFloat(this, 0f, 1f);
	mAnim.setDuration(150);
	mAnim.addUpdateListener(new AnimatorUpdateListener() {
	@Override
	public void onAnimationUpdate(ValueAnimator animation) {
	final float value = (Float) animation.getAnimatedValue();

	final int deltaX = (int) ((value * offsetX) - mOffsetX);
	final int deltaY = (int) ((value * offsetY) - mOffsetY);

	mOffsetX += deltaX;
	mOffsetY += deltaY;
	setScaleX(initialScale + (value * (scale - initialScale)));
	setScaleY(initialScale + (value * (scale - initialScale)));
	if (sDragAlpha != 1f) {
	setAlpha(sDragAlpha * value + (1f - value));
	}

	if (getParent() == null) {
	animation.cancel();
	} else {
	setTranslationX(getTranslationX() + deltaX);
	setTranslationY(getTranslationY() + deltaY);
	}
	}
	});

	mBitmap = Bitmap.createBitmap(bitmap, left, top, width, height);
	setDragRegion(new Rect(0, 0, width, height));

	// The point in our scaled bitmap that the touch events are located
	mRegistrationX = registrationX;
	mRegistrationY = registrationY;

	// Force a measure, because Workspace uses getMeasuredHeight() before the layout pass
	int ms = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
	measure(ms, ms);
	mPaint = new Paint(Paint.FILTER_BITMAP_FLAG);
	}

	public float getOffsetY() {
	return mOffsetY;
	}

	public int getDragRegionLeft() {
	return mDragRegion.left;
	}

	public int getDragRegionTop() {
	return mDragRegion.top;
	}

	public int getDragRegionWidth() {
	return mDragRegion.width();
	}

	public int getDragRegionHeight() {
	return mDragRegion.height();
	}

	public void setDragVisualizeOffset(Point p) {
	mDragVisualizeOffset = p;
	}

	public Point getDragVisualizeOffset() {
	return mDragVisualizeOffset;
	}

	public void setDragRegion(Rect r) {
	mDragRegion = r;
	}

	public Rect getDragRegion() {
	return mDragRegion;
	}

	public float getInitialScale() {
	return mInitialScale;
	}

	public void updateInitialScaleToCurrentScale() {
	mInitialScale = getScaleX();
	}

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

	@Override
	protected void onDraw(Canvas canvas) {
	@SuppressWarnings("all") // suppress dead code warning
	final boolean debug = false;
	if (debug) {
	Paint p = new Paint();
	p.setStyle(Paint.Style.FILL);
	p.setColor(0x66ffffff);
	canvas.drawRect(0, 0, getWidth(), getHeight(), p);
	}

	mHasDrawn = true;
	boolean crossFade = mCrossFadeProgress > 0 && mCrossFadeBitmap != null;
	if (crossFade) {
	int alpha = crossFade ? (int) (255 * (1 - mCrossFadeProgress)) : 255;
	mPaint.setAlpha(alpha);
	}
	canvas.drawBitmap(mBitmap, 0.0f, 0.0f, mPaint);
	if (crossFade) {
	mPaint.setAlpha((int) (255 * mCrossFadeProgress));
	canvas.save();
	float sX = (mBitmap.getWidth() * 1.0f) / mCrossFadeBitmap.getWidth();
	float sY = (mBitmap.getHeight() * 1.0f) / mCrossFadeBitmap.getHeight();
	canvas.scale(sX, sY);
	canvas.drawBitmap(mCrossFadeBitmap, 0.0f, 0.0f, mPaint);
	canvas.restore();
	}
	}

	public void setCrossFadeBitmap(Bitmap crossFadeBitmap) {
	mCrossFadeBitmap = crossFadeBitmap;
	}

	public void crossFade(int duration) {
	ValueAnimator va = LauncherAnimUtils.ofFloat(this, 0f, 1f);
	va.setDuration(duration);
	va.setInterpolator(new DecelerateInterpolator(1.5f));
	va.addUpdateListener(new AnimatorUpdateListener() {
	@Override
	public void onAnimationUpdate(ValueAnimator animation) {
	mCrossFadeProgress = animation.getAnimatedFraction();
	}
	});
	va.start();
	}

	public void setColor(int color) {
	if (mPaint == null) {
	mPaint = new Paint(Paint.FILTER_BITMAP_FLAG);
	}
	if (color != 0) {
	mPaint.setColorFilter(new PorterDuffColorFilter(color, PorterDuff.Mode.SRC_ATOP));
	} else {
	mPaint.setColorFilter(null);
	}
	invalidate();
	}

	public boolean hasDrawn() {
	return mHasDrawn;
	}

	@Override
	public void setAlpha(float alpha) {
	super.setAlpha(alpha);
	mPaint.setAlpha((int) (255 * alpha));
	invalidate();
	}

	/**
	* Create a window containing this view and show it.
	*
	* @param windowToken obtained from v.getWindowToken() from one of your views
	* @param touchX the x coordinate the user touched in DragLayer coordinates
	* @param touchY the y coordinate the user touched in DragLayer coordinates
	*/
	public void show(int touchX, int touchY) {
	mDragLayer.addView(this);

	// Start the pick-up animation
	DragLayer.LayoutParams lp = new DragLayer.LayoutParams(0, 0);
	lp.width = mBitmap.getWidth();
	lp.height = mBitmap.getHeight();
	lp.customPosition = true;
	setLayoutParams(lp);
	setTranslationX(touchX - mRegistrationX);
	setTranslationY(touchY - mRegistrationY);
	// Post the animation to skip other expensive work happening on the first frame
	post(new Runnable() {
	public void run() {
	mAnim.start();
	}
	});
	}

	public void cancelAnimation() {
	if (mAnim != null && mAnim.isRunning()) {
	mAnim.cancel();
	}
	}

	public void resetLayoutParams() {
	mOffsetX = mOffsetY = 0;
	requestLayout();
	}

	/**
	* Move the window containing this view.
	*
	* @param touchX the x coordinate the user touched in DragLayer coordinates
	* @param touchY the y coordinate the user touched in DragLayer coordinates
	*/
	void move(int touchX, int touchY) {
	setTranslationX(touchX - mRegistrationX + (int) mOffsetX);
	setTranslationY(touchY - mRegistrationY + (int) mOffsetY);
	}

	void remove() {
	if (getParent() != null) {
	mDragLayer.removeView(DragView.this);
	}
	}
	}