Home | History | Annotate | Download | only in ui 
      1 /*
      2  * Copyright (C) 2013 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.graphics.Canvas;
     21 import android.graphics.Color;
     22 import android.graphics.Paint;
     23 import android.graphics.RectF;
     24 import android.view.View;
     25 
     26 import com.android.camera2.R;
     27 
     28 /**
     29  * Renders a circular progress bar on the screen.
     30  */
     31 public class ProgressRenderer {
     32     private final int mProgressRadius;
     33     private final Paint mProgressBasePaint;
     34     private final Paint mProgressPaint;
     35 
     36     private RectF mArcBounds = new RectF(0, 0, 1, 1);
     37     private int mProgressAngleDegrees = 270;
     38     private boolean mVisible = false;
     39     private final View mParentView;
     40     private final Runnable mInvalidateParentViewRunnable = new Runnable() {
     41         @Override
     42         public void run() {
     43             mParentView.invalidate();
     44         }
     45     };
     46 
     47     /**
     48      * After we reach 100%, keep on painting the progress for another x milliseconds
     49      * before hiding it.
     50      */
     51     private static final int SHOW_PROGRESS_X_ADDITIONAL_MS = 100;
     52 
     53     public ProgressRenderer(Context context, View parent) {
     54         mParentView = parent;
     55         mProgressRadius = context.getResources().getDimensionPixelSize(R.dimen.pie_progress_radius);
     56         int pieProgressWidth = context.getResources().getDimensionPixelSize(
     57                 R.dimen.pie_progress_width);
     58         mProgressBasePaint = createProgressPaint(pieProgressWidth, 0.2f);
     59         mProgressPaint = createProgressPaint(pieProgressWidth, 1.0f);
     60     }
     61 
     62     /**
     63      * Shows a progress indicator. If the progress is '100', the progress
     64      * indicator will be hidden.
     65      * <p>
     66      * Can be called from any thread.
     67      *
     68      * @param percent the progress in percent (0-100).
     69      */
     70     public void setProgress(int percent) {
     71         // Clamp the value.
     72         percent = Math.min(100, Math.max(percent, 0));
     73         mProgressAngleDegrees = (int) ((360f / 100) * percent);
     74 
     75         // We hide the progress once we drew the 100% state once.
     76         if (percent < 100) {
     77             mVisible = true;
     78         }
     79         mParentView.post(mInvalidateParentViewRunnable);
     80     }
     81 
     82     /**
     83      * Draw the current progress (if < 100%) centered at the given location.
     84      */
     85     public void onDraw(Canvas canvas, int centerX, int centerY) {
     86         if (!mVisible) {
     87             return;
     88         }
     89         mArcBounds = new RectF(centerX - mProgressRadius, centerY - mProgressRadius, centerX
     90                 + mProgressRadius,
     91                 centerY + mProgressRadius);
     92 
     93         canvas.drawCircle(centerX, centerY, mProgressRadius, mProgressBasePaint);
     94         canvas.drawArc(mArcBounds, -90, mProgressAngleDegrees, false, mProgressPaint);
     95 
     96         // After we reached 100%, we paint the progress renderer for another x
     97         // milliseconds until we hide it.
     98         if (mProgressAngleDegrees == 360) {
     99             mVisible = false;
    100             mParentView.postDelayed(
    101                 new Runnable() {
    102                     @Override
    103                     public void run() {
    104                         mParentView.invalidate();
    105                     }
    106                 }, SHOW_PROGRESS_X_ADDITIONAL_MS);
    107         }
    108     }
    109 
    110     /**
    111      * @return Whether the progress renderer is visible.
    112      */
    113     public boolean isVisible() {
    114         return mVisible;
    115     }
    116 
    117     private static Paint createProgressPaint(int width, float alpha) {
    118         Paint paint = new Paint();
    119         paint.setAntiAlias(true);
    120         // 20% alpha.
    121         paint.setColor(Color.argb((int) (alpha * 255), 255, 255, 255));
    122         paint.setStrokeWidth(width);
    123         paint.setStyle(Paint.Style.STROKE);
    124         return paint;
    125     }
    126 }
    127