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      1 /*
      2  * Copyright (C) 2010 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.photoeditor.actions;
     18 
     19 import android.content.Context;
     20 import android.graphics.Canvas;
     21 import android.graphics.Paint;
     22 import android.graphics.Path;
     23 import android.graphics.RectF;
     24 import android.util.AttributeSet;
     25 import android.view.MotionEvent;
     26 import android.view.View;
     27 
     28 import java.util.Vector;
     29 
     30 /**
     31  * A view that track touch motions as paths and paint them as doodles.
     32  */
     33 class DoodleView extends View {
     34 
     35     /**
     36      * Listener of doodle paths.
     37      */
     38     public interface OnDoodleChangeListener {
     39 
     40         void onLastPathChanged(Path path);
     41     }
     42 
     43     private final Vector<ColorPath> colorPaths = new Vector<ColorPath>();
     44     private final Paint paint = ColorPath.createPaint();
     45 
     46     private OnDoodleChangeListener listener;
     47     private RectF clipBounds;
     48     private float lastX;
     49     private float lastY;
     50 
     51     public DoodleView(Context context, AttributeSet attrs) {
     52         super(context, attrs);
     53     }
     54 
     55     public void setOnDoodleChangeListener(OnDoodleChangeListener listener) {
     56         this.listener = listener;
     57     }
     58 
     59     public void startPath(int color) {
     60         // Remove last empty path before adding a new path.
     61         if (!colorPaths.isEmpty() && colorPaths.lastElement().path().isEmpty()) {
     62             colorPaths.remove(colorPaths.size() - 1);
     63         }
     64         colorPaths.add(new ColorPath(color, new Path()));
     65         colorPaths.lastElement().path().moveTo(lastX, lastY);
     66     }
     67 
     68     /**
     69      * Clears clip bounds and paths drawn.
     70      */
     71     public void clear() {
     72         colorPaths.clear();
     73         clipBounds = null;
     74     }
     75 
     76     /**
     77      * Clips bounds for paths being drawn.
     78      */
     79     public void clipBounds(RectF bounds) {
     80         clipBounds = bounds;
     81     }
     82 
     83     private void pathUpdated(Path path) {
     84         invalidate();
     85         if (listener != null) {
     86             listener.onLastPathChanged(path);
     87         }
     88     }
     89 
     90     @Override
     91     public boolean onTouchEvent(MotionEvent event) {
     92         super.onTouchEvent(event);
     93 
     94         if (isEnabled() && !colorPaths.isEmpty()) {
     95             Path path = colorPaths.lastElement().path();
     96             float x = event.getX();
     97             float y = event.getY();
     98 
     99             switch (event.getAction()) {
    100                 case MotionEvent.ACTION_DOWN:
    101                     path.moveTo(x, y);
    102                     pathUpdated(path);
    103                     lastX = x;
    104                     lastY = y;
    105                     break;
    106 
    107                 case MotionEvent.ACTION_MOVE:
    108                     path.quadTo(lastX, lastY, (lastX + x) / 2, (lastY + y) / 2);
    109                     pathUpdated(path);
    110                     lastX = x;
    111                     lastY = y;
    112                     break;
    113 
    114                 case MotionEvent.ACTION_CANCEL:
    115                 case MotionEvent.ACTION_UP:
    116                     // Line to last position with offset to draw at least dots for single clicks.
    117                     path.lineTo(lastX + 1, lastY + 1);
    118                     pathUpdated(path);
    119                     break;
    120             }
    121         }
    122         return true;
    123     }
    124 
    125     @Override
    126     protected void onDraw(Canvas canvas) {
    127         super.onDraw(canvas);
    128 
    129         canvas.save();
    130         if (clipBounds != null) {
    131             canvas.clipRect(clipBounds);
    132         }
    133         for (ColorPath colorPath : colorPaths) {
    134             colorPath.draw(canvas, paint);
    135         }
    136         canvas.restore();
    137     }
    138 }
    139