1 /* 2 * Copyright (C) 2009 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.camera; 18 19 import android.content.Context; 20 import android.graphics.Canvas; 21 import android.graphics.drawable.Drawable; 22 import android.util.AttributeSet; 23 import android.util.Log; 24 import android.view.MotionEvent; 25 import android.view.View; 26 import android.view.animation.AnimationUtils; 27 import android.widget.ImageView; 28 29 /** 30 * A widget which switchs between the {@code Camera} and the {@code VideoCamera} 31 * activities. 32 */ 33 public class Switcher extends ImageView implements View.OnTouchListener { 34 35 @SuppressWarnings("unused") 36 private static final String TAG = "Switcher"; 37 38 /** A callback to be called when the user wants to switch activity. */ 39 public interface OnSwitchListener { 40 // Returns true if the listener agrees that the switch can be changed. onSwitchChanged(Switcher source, boolean onOff)41 public boolean onSwitchChanged(Switcher source, boolean onOff); 42 } 43 44 private static final int ANIMATION_SPEED = 200; 45 private static final long NO_ANIMATION = -1; 46 47 private boolean mSwitch = false; 48 private int mPosition = 0; 49 private long mAnimationStartTime = NO_ANIMATION; 50 private int mAnimationStartPosition; 51 private OnSwitchListener mListener; 52 Switcher(Context context, AttributeSet attrs)53 public Switcher(Context context, AttributeSet attrs) { 54 super(context, attrs); 55 } 56 setSwitch(boolean onOff)57 public void setSwitch(boolean onOff) { 58 if (mSwitch == onOff) return; 59 mSwitch = onOff; 60 invalidate(); 61 } 62 63 // Try to change the switch position. (The client can veto it.) tryToSetSwitch(boolean onOff)64 private void tryToSetSwitch(boolean onOff) { 65 try { 66 if (mSwitch == onOff) return; 67 68 if (mListener != null) { 69 if (!mListener.onSwitchChanged(this, onOff)) { 70 return; 71 } 72 } 73 74 mSwitch = onOff; 75 } finally { 76 startParkingAnimation(); 77 } 78 } 79 setOnSwitchListener(OnSwitchListener listener)80 public void setOnSwitchListener(OnSwitchListener listener) { 81 mListener = listener; 82 } 83 84 @Override onTouchEvent(MotionEvent event)85 public boolean onTouchEvent(MotionEvent event) { 86 if (!isEnabled()) return false; 87 88 final int available = getHeight() - getPaddingTop() - getPaddingBottom() 89 - getDrawable().getIntrinsicHeight(); 90 91 switch (event.getAction()) { 92 case MotionEvent.ACTION_DOWN: 93 mAnimationStartTime = NO_ANIMATION; 94 setPressed(true); 95 trackTouchEvent(event); 96 break; 97 98 case MotionEvent.ACTION_MOVE: 99 trackTouchEvent(event); 100 break; 101 102 case MotionEvent.ACTION_UP: 103 trackTouchEvent(event); 104 tryToSetSwitch(mPosition >= available / 2); 105 setPressed(false); 106 break; 107 108 case MotionEvent.ACTION_CANCEL: 109 tryToSetSwitch(mSwitch); 110 setPressed(false); 111 break; 112 } 113 return true; 114 } 115 startParkingAnimation()116 private void startParkingAnimation() { 117 mAnimationStartTime = AnimationUtils.currentAnimationTimeMillis(); 118 mAnimationStartPosition = mPosition; 119 } 120 trackTouchEvent(MotionEvent event)121 private void trackTouchEvent(MotionEvent event) { 122 Drawable drawable = getDrawable(); 123 int drawableHeight = drawable.getIntrinsicHeight(); 124 final int height = getHeight(); 125 final int available = height - getPaddingTop() - getPaddingBottom() 126 - drawableHeight; 127 int x = (int) event.getY(); 128 mPosition = x - getPaddingTop() - drawableHeight / 2; 129 if (mPosition < 0) mPosition = 0; 130 if (mPosition > available) mPosition = available; 131 invalidate(); 132 } 133 134 @Override onDraw(Canvas canvas)135 protected void onDraw(Canvas canvas) { 136 137 Drawable drawable = getDrawable(); 138 int drawableHeight = drawable.getIntrinsicHeight(); 139 int drawableWidth = drawable.getIntrinsicWidth(); 140 141 if (drawableWidth == 0 || drawableHeight == 0) { 142 return; // nothing to draw (empty bounds) 143 } 144 145 final int available = getHeight() - getPaddingTop() 146 - getPaddingBottom() - drawableHeight; 147 if (mAnimationStartTime != NO_ANIMATION) { 148 long time = AnimationUtils.currentAnimationTimeMillis(); 149 int deltaTime = (int) (time - mAnimationStartTime); 150 mPosition = mAnimationStartPosition + 151 ANIMATION_SPEED * (mSwitch ? deltaTime : -deltaTime) / 1000; 152 if (mPosition < 0) mPosition = 0; 153 if (mPosition > available) mPosition = available; 154 boolean done = (mPosition == (mSwitch ? available : 0)); 155 if (!done) { 156 invalidate(); 157 } else { 158 mAnimationStartTime = NO_ANIMATION; 159 } 160 } else if (!isPressed()){ 161 mPosition = mSwitch ? available : 0; 162 } 163 int offsetTop = getPaddingTop() + mPosition; 164 int offsetLeft = (getWidth() 165 - drawableWidth - getPaddingLeft() - getPaddingRight()) / 2; 166 int saveCount = canvas.getSaveCount(); 167 canvas.save(); 168 canvas.translate(offsetLeft, offsetTop); 169 drawable.draw(canvas); 170 canvas.restoreToCount(saveCount); 171 } 172 173 // Consume the touch events for the specified view. addTouchView(View v)174 public void addTouchView(View v) { 175 v.setOnTouchListener(this); 176 } 177 178 // This implements View.OnTouchListener so we intercept the touch events 179 // and pass them to ourselves. onTouch(View v, MotionEvent event)180 public boolean onTouch(View v, MotionEvent event) { 181 onTouchEvent(event); 182 return true; 183 } 184 } 185