1/*
2 * Copyright (C) 2011 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 com.android.camera.R;
20import com.android.camera.Util;
21
22import android.content.Context;
23import android.content.res.Resources;
24import android.graphics.Canvas;
25import android.graphics.Paint;
26import android.graphics.RectF;
27import android.util.AttributeSet;
28import android.view.MotionEvent;
29import android.view.View;
30
31/**
32 * A view that contains camera zoom control and its layout. In addition to the
33 * zoom control, the method {@link #rotate} is added for rotation animation
34 * which is called in switching between first-level and second-level indicators.
35 */
36public class ZoomControlWheel extends ZoomControl {
37    private static final String TAG = "ZoomControlWheel";
38    private static final int HIGHLIGHT_WIDTH = 4;
39    private static final int HIGHLIGHT_DEGREES = 30;
40    private static final int TRAIL_WIDTH = 2;
41    private static final int ZOOM_IN_ICON_DEGREES = 96;
42    private static final int ZOOM_OUT_ICON_DEGREES = 264;
43    private static final int MAX_SLIDER_ANGLE =
44            ZOOM_OUT_ICON_DEGREES - (HIGHLIGHT_DEGREES / 2);
45    private static final int MIN_SLIDER_ANGLE =
46            ZOOM_IN_ICON_DEGREES + (HIGHLIGHT_DEGREES / 2);
47    private static final int DEFAULT_SLIDER_POSITION = MAX_SLIDER_ANGLE;
48    private static final float EDGE_STROKE_WIDTH = 6f;
49    private static final double BUFFER_RADIANS = Math.toRadians(HIGHLIGHT_DEGREES / 2);
50    private static final double SLIDER_RANGE =
51            Math.toRadians(MAX_SLIDER_ANGLE - MIN_SLIDER_ANGLE);
52    private double mSliderRadians = DEFAULT_SLIDER_POSITION;
53
54    private final int HIGHLIGHT_COLOR;
55    private final int TRAIL_COLOR;
56
57    // The center of the shutter button.
58    private int mCenterX, mCenterY;
59    // The width of the wheel stroke.
60    private int mStrokeWidth;
61    private double mShutterButtonRadius;
62    private double mWheelRadius;
63    private Paint mBackgroundPaint;
64    private RectF mBackgroundRect;
65
66    private double mRotateAngle;
67
68    public ZoomControlWheel(Context context, AttributeSet attrs) {
69        super(context, attrs);
70        setWillNotDraw(false);
71
72        mBackgroundPaint = new Paint();
73        mBackgroundPaint.setStyle(Paint.Style.STROKE);
74        mBackgroundPaint.setAntiAlias(true);
75
76        mBackgroundRect = new RectF();
77        Resources resources = context.getResources();
78        HIGHLIGHT_COLOR = resources.getColor(R.color.review_control_pressed_color);
79        TRAIL_COLOR = resources.getColor(R.color.icon_disabled_color);
80
81        mShutterButtonRadius = IndicatorControlWheelContainer.SHUTTER_BUTTON_RADIUS;
82        mStrokeWidth = Util.dpToPixel(IndicatorControlWheelContainer.STROKE_WIDTH);
83        mWheelRadius = mShutterButtonRadius + mStrokeWidth * 0.5;
84    }
85
86    @Override
87    public boolean dispatchTouchEvent(MotionEvent event) {
88        if (!onFilterTouchEventForSecurity(event) || !isEnabled()) return false;
89        int action = event.getAction();
90
91        double dx = event.getX() - mCenterX;
92        double dy = mCenterY - event.getY();
93        double radius = Math.sqrt(dx * dx + dy * dy);
94        // Ignore the event if too far from the shutter button.
95        double angle = Math.atan2(dy, dx);
96        if (angle < 0) angle += (2 * Math.PI);
97        mSliderRadians = getSliderDrawAngle(angle);
98
99        // We assume the slider button is pressed all the time when the
100        // zoom control is active. So we take care of the following events
101        // only.
102        switch (action) {
103            case MotionEvent.ACTION_OUTSIDE:
104            case MotionEvent.ACTION_UP:
105            case MotionEvent.ACTION_CANCEL:
106                closeZoomControl();
107                break;
108            case MotionEvent.ACTION_MOVE:
109                performZoom((Math.toRadians(MAX_SLIDER_ANGLE)
110                        - mSliderRadians) / SLIDER_RANGE);
111                requestLayout();
112        }
113        return true;
114    }
115
116    @Override
117    public void startZoomControl() {
118        super.startZoomControl();
119        mSliderRadians = Math.toRadians(DEFAULT_SLIDER_POSITION);
120    }
121
122    private void layoutIcon(View view, double radian) {
123        // Rotate the wheel with the angle when the wheel is rotating or
124        // the indicator control is in the second-level.
125        radian += mRotateAngle;
126        int x = mCenterX + (int)(mWheelRadius * Math.cos(radian));
127        int y = mCenterY - (int)(mWheelRadius * Math.sin(radian));
128        int width = view.getMeasuredWidth();
129        int height = view.getMeasuredHeight();
130        view.layout(x - width / 2, y - height / 2, x + width / 2,
131                y + height / 2);
132    }
133
134    private double getSliderDrawAngle(double sliderAngle) {
135        if (sliderAngle > Math.toRadians(MAX_SLIDER_ANGLE)) {
136            return Math.toRadians(MAX_SLIDER_ANGLE);
137        } else if (sliderAngle < Math.toRadians(MIN_SLIDER_ANGLE)) {
138            return Math.toRadians(MIN_SLIDER_ANGLE);
139        }
140        return sliderAngle;
141    }
142
143    @Override
144    protected void onLayout(
145            boolean changed, int left, int top, int right, int bottom) {
146        mCenterX = right - left - Util.dpToPixel(
147                IndicatorControlWheelContainer.FULL_WHEEL_RADIUS);
148        mCenterY = (bottom - top) / 2;
149        layoutIcon(mZoomIn, Math.toRadians(ZOOM_IN_ICON_DEGREES));
150        layoutIcon(mZoomOut, Math.toRadians(ZOOM_OUT_ICON_DEGREES));
151        layoutIcon(mZoomSlider, getSliderDrawAngle(mSliderRadians));
152   }
153
154    private double getZoomIndexAngle() {
155        if (mZoomMax == 0) return Math.PI;
156        return Math.toRadians(MAX_SLIDER_ANGLE -
157                (MAX_SLIDER_ANGLE - MIN_SLIDER_ANGLE) * mZoomIndex / mZoomMax);
158    }
159
160    private void drawArc(Canvas canvas, int startAngle, int sweepAngle,
161            double radius, int color, int width) {
162        mBackgroundRect.set((float) (mCenterX - radius), (float) (mCenterY - radius),
163                (float) (mCenterX + radius), (float) (mCenterY + radius));
164        mBackgroundPaint.setStrokeWidth(width);
165        mBackgroundPaint.setStrokeCap(Paint.Cap.ROUND);
166        mBackgroundPaint.setColor(color);
167        canvas.drawArc(mBackgroundRect, startAngle, sweepAngle, false, mBackgroundPaint);
168    }
169
170    @Override
171    protected void onDraw(Canvas canvas) {
172        // Draw the slider trail.
173        int startAngle = -MAX_SLIDER_ANGLE - (int) Math.toDegrees(mRotateAngle);
174        int radians = (MAX_SLIDER_ANGLE - MIN_SLIDER_ANGLE);
175        if ((startAngle + radians) > 0) radians = -startAngle;
176        drawArc(canvas, startAngle, radians,
177                mWheelRadius, TRAIL_COLOR, TRAIL_WIDTH);
178        super.onDraw(canvas);
179    }
180
181    public void rotate(double angle) {
182        mRotateAngle = angle;
183        requestLayout();
184    }
185}
186