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      1 /*
      2  * Copyright (C) 2008 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.calculator2;
     18 
     19 import android.content.Context;
     20 import android.graphics.Canvas;
     21 import android.graphics.Paint;
     22 import android.graphics.Paint.Style;
     23 import android.util.AttributeSet;
     24 import android.widget.Button;
     25 import android.view.View.OnClickListener;
     26 import android.view.View;
     27 import android.view.MotionEvent;
     28 import android.content.res.Resources;
     29 
     30 /**
     31  * Button with click-animation effect.
     32  */
     33 class ColorButton extends Button implements OnClickListener {
     34     int CLICK_FEEDBACK_COLOR;
     35     static final int CLICK_FEEDBACK_INTERVAL = 10;
     36     static final int CLICK_FEEDBACK_DURATION = 350;
     37 
     38     float mTextX;
     39     float mTextY;
     40     long mAnimStart;
     41     OnClickListener mListener;
     42     Paint mFeedbackPaint;
     43 
     44     public ColorButton(Context context, AttributeSet attrs) {
     45         super(context, attrs);
     46         Calculator calc = (Calculator) context;
     47         init(calc);
     48         mListener = calc.mListener;
     49         setOnClickListener(this);
     50     }
     51 
     52     public void onClick(View view) {
     53         mListener.onClick(this);
     54     }
     55 
     56     private void init(Calculator calc) {
     57         Resources res = getResources();
     58 
     59         CLICK_FEEDBACK_COLOR = res.getColor(R.color.magic_flame);
     60         mFeedbackPaint = new Paint();
     61         mFeedbackPaint.setStyle(Style.STROKE);
     62         mFeedbackPaint.setStrokeWidth(2);
     63         getPaint().setColor(res.getColor(R.color.button_text));
     64 
     65         mAnimStart = -1;
     66 
     67         calc.adjustFontSize(this);
     68     }
     69 
     70 
     71     @Override
     72     public void onSizeChanged(int w, int h, int oldW, int oldH) {
     73         measureText();
     74     }
     75 
     76     private void measureText() {
     77         Paint paint = getPaint();
     78         mTextX = (getWidth() - paint.measureText(getText().toString())) / 2;
     79         mTextY = (getHeight() - paint.ascent() - paint.descent()) / 2;
     80     }
     81 
     82     @Override
     83     protected void onTextChanged(CharSequence text, int start, int before, int after) {
     84         measureText();
     85     }
     86 
     87     private void drawMagicFlame(int duration, Canvas canvas) {
     88         int alpha = 255 - 255 * duration / CLICK_FEEDBACK_DURATION;
     89         int color = CLICK_FEEDBACK_COLOR | (alpha << 24);
     90 
     91         mFeedbackPaint.setColor(color);
     92         canvas.drawRect(1, 1, getWidth() - 1, getHeight() - 1, mFeedbackPaint);
     93     }
     94 
     95     @Override
     96     public void onDraw(Canvas canvas) {
     97         if (mAnimStart != -1) {
     98             int animDuration = (int) (System.currentTimeMillis() - mAnimStart);
     99 
    100             if (animDuration >= CLICK_FEEDBACK_DURATION) {
    101                 mAnimStart = -1;
    102             } else {
    103                 drawMagicFlame(animDuration, canvas);
    104                 postInvalidateDelayed(CLICK_FEEDBACK_INTERVAL);
    105             }
    106         } else if (isPressed()) {
    107             drawMagicFlame(0, canvas);
    108         }
    109 
    110         CharSequence text = getText();
    111         canvas.drawText(text, 0, text.length(), mTextX, mTextY, getPaint());
    112     }
    113 
    114     public void animateClickFeedback() {
    115         mAnimStart = System.currentTimeMillis();
    116         invalidate();
    117     }
    118 
    119     @Override
    120     public boolean onTouchEvent(MotionEvent event) {
    121         boolean result = super.onTouchEvent(event);
    122 
    123         switch (event.getAction()) {
    124             case MotionEvent.ACTION_UP:
    125                 animateClickFeedback();
    126                 break;
    127             case MotionEvent.ACTION_DOWN:
    128             case MotionEvent.ACTION_CANCEL:
    129                 invalidate();
    130                 break;
    131         }
    132 
    133         return result;
    134     }
    135 }
    136