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      1 /*
      2  * Copyright (C) 2012 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.ui;
     18 
     19 import android.content.Context;
     20 import android.content.res.Resources;
     21 import android.graphics.Canvas;
     22 import android.graphics.Color;
     23 import android.graphics.Paint;
     24 import android.graphics.Rect;
     25 import android.view.ScaleGestureDetector;
     26 
     27 import com.android.gallery3d.R;
     28 
     29 public class ZoomRenderer extends OverlayRenderer
     30         implements ScaleGestureDetector.OnScaleGestureListener {
     31 
     32     private static final String TAG = "CAM_Zoom";
     33 
     34     private int mMaxZoom;
     35     private int mMinZoom;
     36     private OnZoomChangedListener mListener;
     37 
     38     private ScaleGestureDetector mDetector;
     39     private Paint mPaint;
     40     private Paint mTextPaint;
     41     private int mCircleSize;
     42     private int mCenterX;
     43     private int mCenterY;
     44     private float mMaxCircle;
     45     private float mMinCircle;
     46     private int mInnerStroke;
     47     private int mOuterStroke;
     48     private int mZoomSig;
     49     private int mZoomFraction;
     50     private Rect mTextBounds;
     51 
     52     public interface OnZoomChangedListener {
     53         void onZoomStart();
     54         void onZoomEnd();
     55         void onZoomValueChanged(int index);  // only for immediate zoom
     56     }
     57 
     58     public ZoomRenderer(Context ctx) {
     59         Resources res = ctx.getResources();
     60         mPaint = new Paint();
     61         mPaint.setAntiAlias(true);
     62         mPaint.setColor(Color.WHITE);
     63         mPaint.setStyle(Paint.Style.STROKE);
     64         mTextPaint = new Paint(mPaint);
     65         mTextPaint.setStyle(Paint.Style.FILL);
     66         mTextPaint.setTextSize(res.getDimensionPixelSize(R.dimen.zoom_font_size));
     67         mTextPaint.setTextAlign(Paint.Align.LEFT);
     68         mTextPaint.setAlpha(192);
     69         mInnerStroke = res.getDimensionPixelSize(R.dimen.focus_inner_stroke);
     70         mOuterStroke = res.getDimensionPixelSize(R.dimen.focus_outer_stroke);
     71         mDetector = new ScaleGestureDetector(ctx, this);
     72         mMinCircle = res.getDimensionPixelSize(R.dimen.zoom_ring_min);
     73         mTextBounds = new Rect();
     74         setVisible(false);
     75     }
     76 
     77     // set from module
     78     public void setZoomMax(int zoomMaxIndex) {
     79         mMaxZoom = zoomMaxIndex;
     80         mMinZoom = 0;
     81     }
     82 
     83     public void setZoom(int index) {
     84         mCircleSize = (int) (mMinCircle + index * (mMaxCircle - mMinCircle) / (mMaxZoom - mMinZoom));
     85     }
     86 
     87     public void setZoomValue(int value) {
     88         value = value / 10;
     89         mZoomSig = value / 10;
     90         mZoomFraction = value % 10;
     91     }
     92 
     93     public void setOnZoomChangeListener(OnZoomChangedListener listener) {
     94         mListener = listener;
     95     }
     96 
     97     @Override
     98     public void layout(int l, int t, int r, int b) {
     99         super.layout(l, t, r, b);
    100         mCenterX = (r - l) / 2;
    101         mCenterY = (b - t) / 2;
    102         mMaxCircle = Math.min(getWidth(), getHeight());
    103         mMaxCircle = (mMaxCircle - mMinCircle) / 2;
    104     }
    105 
    106     public boolean isScaling() {
    107         return mDetector.isInProgress();
    108     }
    109 
    110     @Override
    111     public void onDraw(Canvas canvas) {
    112         mPaint.setStrokeWidth(mInnerStroke);
    113         canvas.drawCircle(mCenterX, mCenterY, mMinCircle, mPaint);
    114         canvas.drawCircle(mCenterX, mCenterY, mMaxCircle, mPaint);
    115         canvas.drawLine(mCenterX - mMinCircle, mCenterY,
    116                 mCenterX - mMaxCircle - 4, mCenterY, mPaint);
    117         mPaint.setStrokeWidth(mOuterStroke);
    118         canvas.drawCircle((float) mCenterX, (float) mCenterY,
    119                 (float) mCircleSize, mPaint);
    120         String txt = mZoomSig+"."+mZoomFraction+"x";
    121         mTextPaint.getTextBounds(txt, 0, txt.length(), mTextBounds);
    122         canvas.drawText(txt, mCenterX - mTextBounds.centerX(), mCenterY - mTextBounds.centerY(),
    123                 mTextPaint);
    124     }
    125 
    126     @Override
    127     public boolean onScale(ScaleGestureDetector detector) {
    128         final float sf = detector.getScaleFactor();
    129         float circle = (int) (mCircleSize * sf * sf);
    130         circle = Math.max(mMinCircle, circle);
    131         circle = Math.min(mMaxCircle, circle);
    132         if (mListener != null && (int) circle != mCircleSize) {
    133             mCircleSize = (int) circle;
    134             int zoom = mMinZoom + (int) ((mCircleSize - mMinCircle) * (mMaxZoom - mMinZoom) / (mMaxCircle - mMinCircle));
    135             mListener.onZoomValueChanged(zoom);
    136         }
    137         return true;
    138     }
    139 
    140     @Override
    141     public boolean onScaleBegin(ScaleGestureDetector detector) {
    142         setVisible(true);
    143         if (mListener != null) {
    144             mListener.onZoomStart();
    145         }
    146         update();
    147         return true;
    148     }
    149 
    150     @Override
    151     public void onScaleEnd(ScaleGestureDetector detector) {
    152         setVisible(false);
    153         if (mListener != null) {
    154             mListener.onZoomEnd();
    155         }
    156     }
    157 
    158 }
    159