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      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 
     17 package com.android.camera.ui;
     18 
     19 import com.android.camera.R;
     20 import com.android.camera.Util;
     21 
     22 import android.content.Context;
     23 import android.content.res.Resources;
     24 import android.graphics.Canvas;
     25 import android.graphics.Paint;
     26 import android.graphics.RectF;
     27 import android.util.AttributeSet;
     28 import android.view.MotionEvent;
     29 import 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  */
     36 public 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