1 /** 2 * Copyright (C) 2022 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.settingslib.qrcode; 18 19 import android.content.Context; 20 import android.graphics.Bitmap; 21 import android.graphics.Canvas; 22 import android.graphics.Paint; 23 import android.graphics.PorterDuff; 24 import android.graphics.PorterDuffXfermode; 25 import android.graphics.RectF; 26 import android.util.AttributeSet; 27 import android.util.Log; 28 import android.util.TypedValue; 29 import android.view.View; 30 31 import com.android.settingslib.R; 32 33 public class QrDecorateView extends View { 34 private static final float CORNER_STROKE_WIDTH = 4f; // 4dp 35 private static final float CORNER_LINE_LENGTH = 264f; // 264dp 36 private static final float CORNER_RADIUS = 16f; // 16dp 37 private static final String TAG = "QrDecorateView"; 38 39 private final int mCornerColor; 40 private final int mFocusedCornerColor; 41 private final int mBackgroundColor; 42 43 private final Paint mStrokePaint; 44 private final Paint mTransparentPaint; 45 private final Paint mBackgroundPaint; 46 47 private final float mRadius; 48 private final float mInnerRadius; 49 50 private Bitmap mMaskBitmap; 51 private Canvas mMaskCanvas; 52 53 private RectF mOuterFrame; 54 private RectF mInnerFrame; 55 56 private boolean mFocused; 57 QrDecorateView(Context context)58 public QrDecorateView(Context context) { 59 this(context, null); 60 } 61 QrDecorateView(Context context, AttributeSet attrs)62 public QrDecorateView(Context context, AttributeSet attrs) { 63 this(context, attrs, 0); 64 } 65 QrDecorateView(Context context, AttributeSet attrs, int defStyleAttr)66 public QrDecorateView(Context context, AttributeSet attrs, int defStyleAttr) { 67 this(context, attrs, defStyleAttr, 0); 68 } 69 QrDecorateView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes)70 public QrDecorateView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) { 71 super(context, attrs, defStyleAttr, defStyleRes); 72 73 mFocused = false; 74 mRadius = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, CORNER_RADIUS, 75 getResources().getDisplayMetrics()); 76 // Inner radius needs to minus stroke width for keeping the width of border consistent. 77 mInnerRadius = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 78 CORNER_RADIUS - CORNER_STROKE_WIDTH, getResources().getDisplayMetrics()); 79 80 mCornerColor = context.getResources().getColor(R.color.qr_corner_line_color); 81 mFocusedCornerColor = context.getResources().getColor(R.color.qr_focused_corner_line_color); 82 mBackgroundColor = context.getResources().getColor(R.color.qr_background_color); 83 84 mStrokePaint = new Paint(); 85 mStrokePaint.setAntiAlias(true); 86 87 mTransparentPaint = new Paint(); 88 mTransparentPaint.setAntiAlias(true); 89 mTransparentPaint.setColor(getResources().getColor(android.R.color.transparent)); 90 mTransparentPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR)); 91 92 mBackgroundPaint = new Paint(); 93 mBackgroundPaint.setColor(mBackgroundColor); 94 } 95 96 @Override onLayout(boolean changed, int left, int top, int right, int bottom)97 protected void onLayout(boolean changed, int left, int top, int right, int bottom) { 98 super.onLayout(changed, left, top, right, bottom); 99 if (getWidth() <= 0 || getHeight() <= 0) { 100 Log.e(TAG, "width and height must be > 0"); 101 return; 102 } 103 104 if (mMaskBitmap == null) { 105 mMaskBitmap = Bitmap.createBitmap(getWidth(), getHeight(), Bitmap.Config.ARGB_8888); 106 mMaskCanvas = new Canvas(mMaskBitmap); 107 } 108 109 calculateFramePos(); 110 } 111 112 @Override onDraw(Canvas canvas)113 protected void onDraw(Canvas canvas) { 114 if (mMaskCanvas != null && mMaskBitmap != null) { 115 // Set frame line color. 116 mStrokePaint.setColor(mFocused ? mFocusedCornerColor : mCornerColor); 117 // Draw background color. 118 mMaskCanvas.drawColor(mBackgroundColor); 119 // Draw outer corner. 120 mMaskCanvas.drawRoundRect(mOuterFrame, mRadius, mRadius, mStrokePaint); 121 // Draw inner transparent corner. 122 mMaskCanvas.drawRoundRect(mInnerFrame, mInnerRadius, mInnerRadius, mTransparentPaint); 123 124 canvas.drawBitmap(mMaskBitmap, 0, 0, mBackgroundPaint); 125 } 126 super.onDraw(canvas); 127 } 128 calculateFramePos()129 private void calculateFramePos() { 130 final int centralX = getWidth() / 2; 131 final int centralY = getHeight() / 2; 132 final float cornerLineLength = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 133 CORNER_LINE_LENGTH, getResources().getDisplayMetrics()) / 2; 134 final float strokeWidth = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 135 CORNER_STROKE_WIDTH, getResources().getDisplayMetrics()); 136 137 mOuterFrame = new RectF(centralX - cornerLineLength, centralY - cornerLineLength, 138 centralX + cornerLineLength, centralY + cornerLineLength); 139 mInnerFrame = new RectF(mOuterFrame.left + strokeWidth, mOuterFrame.top + strokeWidth, 140 mOuterFrame.right - strokeWidth, mOuterFrame.bottom - strokeWidth); 141 } 142 143 // Draws green lines if focused. Otherwise, draws white lines. setFocused(boolean focused)144 public void setFocused(boolean focused) { 145 mFocused = focused; 146 invalidate(); 147 } 148 } 149