content: /*
   * Copyright (C) 2015 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.android.setupwizardlib;
  
  import android.annotation.SuppressLint;
  import android.content.Context;
  import android.content.res.TypedArray;
  import android.graphics.Bitmap;
  import android.graphics.Canvas;
  import android.graphics.Color;
  import android.graphics.ColorFilter;
  import android.graphics.Paint;
  import android.graphics.Path;
  import android.graphics.PixelFormat;
  import android.graphics.PorterDuff;
  import android.graphics.PorterDuffXfermode;
  import android.graphics.Rect;
  import android.graphics.drawable.Drawable;
  import android.os.Build;
  import androidx.annotation.NonNull;
  import androidx.annotation.VisibleForTesting;
  import java.lang.ref.SoftReference;
  
  /**
   * This class draws the GLIF pattern used as the status bar background for phones and background for
   * tablets in GLIF layout.
   */
  public class GlifPatternDrawable extends Drawable {
    /*
     * This class essentially implements a simple SVG in Java code, with some special handling of
     * scaling when given different bounds.
     */
  
    /* static section */
  
    @SuppressLint("InlinedApi")
    private static final int[] ATTRS_PRIMARY_COLOR = new int[] {android.R.attr.colorPrimary};
  
    private static final float VIEWBOX_HEIGHT = 768f;
    private static final float VIEWBOX_WIDTH = 1366f;
    // X coordinate of scale focus, as a fraction of the width. (Range is 0 - 1)
    private static final float SCALE_FOCUS_X = .146f;
    // Y coordinate of scale focus, as a fraction of the height. (Range is 0 - 1)
    private static final float SCALE_FOCUS_Y = .228f;
  
    // Alpha component of the color to be drawn, on top of the grayscale pattern. (Range is 0 - 1)
    private static final float COLOR_ALPHA = .8f;
    // Int version of COLOR_ALPHA. (Range is 0 - 255)
    private static final int COLOR_ALPHA_INT = (int) (COLOR_ALPHA * 255);
  
    // Cap the bitmap size, such that it won't hurt the performance too much
    // and it won't crash due to a very large scale.
    // The drawable will look blurry above this size.
    // This is a multiplier applied on top of the viewbox size.
    // Resulting max cache size = (1.5 x 1366, 1.5 x 768) = (2049, 1152)
    private static final float MAX_CACHED_BITMAP_SCALE = 1.5f;
  
    private static final int NUM_PATHS = 7;
  
    private static SoftReference<Bitmap> bitmapCache;
    private static Path[] patternPaths;
    private static int[] patternLightness;
  
    public static GlifPatternDrawable getDefault(Context context) {
      int colorPrimary = 0;
      if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        final TypedArray a = context.obtainStyledAttributes(ATTRS_PRIMARY_COLOR);
        colorPrimary = a.getColor(0, Color.BLACK);
        a.recycle();
      }
      return new GlifPatternDrawable(colorPrimary);
    }
  
    @VisibleForTesting
    public static void invalidatePattern() {
      bitmapCache = null;
    }
  
    /* non-static section */
  
    private int color;
    private final Paint tempPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
  
    public GlifPatternDrawable(int color) {
      setColor(color);
    }
  
    @Override
    public void draw(@NonNull Canvas canvas) {
      final Rect bounds = getBounds();
      int drawableWidth = bounds.width();
      int drawableHeight = bounds.height();
      Bitmap bitmap = null;
      if (bitmapCache != null) {
        bitmap = bitmapCache.get();
      }
      if (bitmap != null) {
        final int bitmapWidth = bitmap.getWidth();
        final int bitmapHeight = bitmap.getHeight();
        // Invalidate the cache if this drawable is bigger and we can still create a bigger
        // cache.
        if (drawableWidth > bitmapWidth && bitmapWidth < VIEWBOX_WIDTH * MAX_CACHED_BITMAP_SCALE) {
          bitmap = null;
        } else if (drawableHeight > bitmapHeight
            && bitmapHeight < VIEWBOX_HEIGHT * MAX_CACHED_BITMAP_SCALE) {
          bitmap = null;
        }
      }
  
      if (bitmap == null) {
        // Reset the paint so it can be used to draw the paths in renderOnCanvas
        tempPaint.reset();
  
        bitmap = createBitmapCache(drawableWidth, drawableHeight);
        bitmapCache = new SoftReference<>(bitmap);
  
        // Reset the paint to so it can be used to draw the bitmap
        tempPaint.reset();
      }
  
      canvas.save();
      canvas.clipRect(bounds);
  
      scaleCanvasToBounds(canvas, bitmap, bounds);
      canvas.drawColor(Color.BLACK);
      tempPaint.setColor(Color.WHITE);
      canvas.drawBitmap(bitmap, 0, 0, tempPaint);
      canvas.drawColor(color);
  
      canvas.restore();
    }
  
    @VisibleForTesting
    public Bitmap createBitmapCache(int drawableWidth, int drawableHeight) {
      float scaleX = drawableWidth / VIEWBOX_WIDTH;
      float scaleY = drawableHeight / VIEWBOX_HEIGHT;
      float scale = Math.max(scaleX, scaleY);
      scale = Math.min(MAX_CACHED_BITMAP_SCALE, scale);
  
      int scaledWidth = (int) (VIEWBOX_WIDTH * scale);
      int scaledHeight = (int) (VIEWBOX_HEIGHT * scale);
  
      // Use ALPHA_8 mask to save memory, since the pattern is grayscale only anyway.
      Bitmap bitmap = Bitmap.createBitmap(scaledWidth, scaledHeight, Bitmap.Config.ALPHA_8);
      Canvas bitmapCanvas = new Canvas(bitmap);
      renderOnCanvas(bitmapCanvas, scale);
      return bitmap;
    }
  
    private void renderOnCanvas(Canvas canvas, float scale) {
      canvas.save();
      canvas.scale(scale, scale);
  
      tempPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC));
  
      // Draw the pattern by creating the paths, adjusting the colors and drawing them. The path
      // values are extracted from the SVG of the pattern file.
  
      if (patternPaths == null) {
        patternPaths = new Path[NUM_PATHS];
        // Lightness values of the pattern, range 0 - 255
        patternLightness = new int[] {10, 40, 51, 66, 91, 112, 130};
  
        Path p = patternPaths[0] = new Path();
        p.moveTo(1029.4f, 357.5f);
        p.lineTo(1366f, 759.1f);
        p.lineTo(1366f, 0f);
        p.lineTo(1137.7f, 0f);
        p.close();
  
        p = patternPaths[1] = new Path();
        p.moveTo(1138.1f, 0f);
        p.rLineTo(-144.8f, 768f);
        p.rLineTo(372.7f, 0f);
        p.rLineTo(0f, -524f);
        p.cubicTo(1290.7f, 121.6f, 1219.2f, 41.1f, 1178.7f, 0f);
        p.close();
  
        p = patternPaths[2] = new Path();
        p.moveTo(949.8f, 768f);
        p.rCubicTo(92.6f, -170.6f, 213f, -440.3f, 269.4f, -768f);
        p.lineTo(585f, 0f);
        p.rLineTo(2.1f, 766f);
        p.close();
  
        p = patternPaths[3] = new Path();
        p.moveTo(471.1f, 768f);
        p.rMoveTo(704.5f, 0f);
        p.cubicTo(1123.6f, 563.3f, 1027.4f, 275.2f, 856.2f, 0f);
        p.lineTo(476.4f, 0f);
        p.rLineTo(-5.3f, 768f);
        p.close();
  
        p = patternPaths[4] = new Path();
        p.moveTo(323.1f, 768f);
        p.moveTo(777.5f, 768f);
        p.cubicTo(661.9f, 348.8f, 427.2f, 21.4f, 401.2f, 25.4f);
        p.lineTo(323.1f, 768f);
        p.close();
  
        p = patternPaths[5] = new Path();
        p.moveTo(178.44286f, 766.8571f);
        p.lineTo(308.7f, 768f);
        p.cubicTo(381.7f, 604.6f, 481.6f, 344.3f, 562.2f, 0f);
        p.lineTo(0f, 0f);
        p.close();
  
        p = patternPaths[6] = new Path();
        p.moveTo(146f, 0f);
        p.lineTo(0f, 0f);
        p.lineTo(0f, 768f);
        p.lineTo(394.2f, 768f);
        p.cubicTo(327.7f, 475.3f, 228.5f, 201f, 146f, 0f);
        p.close();
      }
  
      for (int i = 0; i < NUM_PATHS; i++) {
        // Color is 0xAARRGGBB, so alpha << 24 will create a color with (alpha)% black.
        // Although the color components don't really matter, since the backing bitmap cache is
        // ALPHA_8.
        tempPaint.setColor(patternLightness[i] << 24);
        canvas.drawPath(patternPaths[i], tempPaint);
      }
  
      canvas.restore();
      tempPaint.reset();
    }
  
    @VisibleForTesting
    public void scaleCanvasToBounds(Canvas canvas, Bitmap bitmap, Rect drawableBounds) {
      int bitmapWidth = bitmap.getWidth();
      int bitmapHeight = bitmap.getHeight();
      float scaleX = drawableBounds.width() / (float) bitmapWidth;
      float scaleY = drawableBounds.height() / (float) bitmapHeight;
  
      // First scale both sides to fit independently.
      canvas.scale(scaleX, scaleY);
      if (scaleY > scaleX) {
        // Adjust x-scale to maintain aspect ratio using the pivot, so that more of the texture
        // and less of the blank space on the left edge is seen.
        canvas.scale(scaleY / scaleX, 1f, SCALE_FOCUS_X * bitmapWidth, 0f);
      } else if (scaleX > scaleY) {
        // Adjust y-scale to maintain aspect ratio using the pivot, so that an intersection of
        // two "circles" can always be seen.
        canvas.scale(1f, scaleX / scaleY, 0f, SCALE_FOCUS_Y * bitmapHeight);
      }
    }
  
    @Override
    public void setAlpha(int i) {
      // Ignore
    }
  
    @Override
    public void setColorFilter(ColorFilter colorFilter) {
      // Ignore
    }
  
    @Override
    public int getOpacity() {
      return PixelFormat.UNKNOWN;
    }
  
    /**
     * Sets the color used as the base color of this pattern drawable. The alpha component of the
     * color will be ignored.
     */
    public void setColor(int color) {
      final int r = Color.red(color);
      final int g = Color.green(color);
      final int b = Color.blue(color);
      this.color = Color.argb(COLOR_ALPHA_INT, r, g, b);
      invalidateSelf();
    }
  
    /**
     * @return The color used as the base color of this pattern drawable. The alpha component of this
     *     is always 255.
     */
    public int getColor() {
      return Color.argb(255, Color.red(color), Color.green(color), Color.blue(color));
    }
  }
  