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
17package com.android.camera.ui;
18
19import android.content.Context;
20import android.content.res.Resources;
21import android.graphics.Canvas;
22import android.graphics.Color;
23import android.graphics.Paint;
24import android.graphics.Rect;
25import android.view.ScaleGestureDetector;
26
27import com.android.camera.R;
28
29public 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