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.view;
  
  import android.annotation.TargetApi;
  import android.content.Context;
  import android.content.pm.ApplicationInfo;
  import android.content.res.TypedArray;
  import android.graphics.Canvas;
  import android.graphics.Rect;
  import android.graphics.drawable.Drawable;
  import android.os.Build.VERSION;
  import android.os.Build.VERSION_CODES;
  import android.util.AttributeSet;
  import android.util.LayoutDirection;
  import android.view.Gravity;
  import android.view.ViewOutlineProvider;
  import android.widget.FrameLayout;
  import com.android.setupwizardlib.R;
  
  /**
   * Class to draw the illustration of setup wizard. The {@code aspectRatio} attribute determines the
   * aspect ratio of the top padding, which leaves space for the illustration. Draws the illustration
   * drawable to fit the width of the view and fills the rest with the background.
   *
   * <p>If an aspect ratio is set, then the aspect ratio of the source drawable is maintained.
   * Otherwise the aspect ratio will be ignored, only increasing the width of the illustration.
   */
  public class Illustration extends FrameLayout {
  
    // Size of the baseline grid in pixels
    private float baselineGridSize;
    private Drawable background;
    private Drawable illustration;
    private final Rect viewBounds = new Rect();
    private final Rect illustrationBounds = new Rect();
    private float scale = 1.0f;
    private float aspectRatio = 0.0f;
  
    public Illustration(Context context) {
      super(context);
      init(null, 0);
    }
  
    public Illustration(Context context, AttributeSet attrs) {
      super(context, attrs);
      init(attrs, 0);
    }
  
    @TargetApi(VERSION_CODES.HONEYCOMB)
    public Illustration(Context context, AttributeSet attrs, int defStyleAttr) {
      super(context, attrs, defStyleAttr);
      init(attrs, defStyleAttr);
    }
  
    // All the constructors delegate to this init method. The 3-argument constructor is not
    // available in FrameLayout before v11, so call super with the exact same arguments.
    private void init(AttributeSet attrs, int defStyleAttr) {
      if (attrs != null) {
        TypedArray a =
            getContext().obtainStyledAttributes(attrs, R.styleable.SuwIllustration, defStyleAttr, 0);
        aspectRatio = a.getFloat(R.styleable.SuwIllustration_suwAspectRatio, 0.0f);
        a.recycle();
      }
      // Number of pixels of the 8dp baseline grid as defined in material design specs
      baselineGridSize = getResources().getDisplayMetrics().density * 8;
      setWillNotDraw(false);
    }
  
    /**
     * The background will be drawn to fill up the rest of the view. It will also be scaled by the
     * same amount as the foreground so their textures look the same.
     */
    // Override the deprecated setBackgroundDrawable method to support API < 16. View.setBackground
    // forwards to setBackgroundDrawable in the framework implementation.
    @SuppressWarnings("deprecation")
    @Override
    public void setBackgroundDrawable(Drawable background) {
      if (background == this.background) {
        return;
      }
      this.background = background;
      invalidate();
      requestLayout();
    }
  
    /**
     * Sets the drawable used as the illustration. The drawable is expected to have intrinsic width
     * and height defined and will be scaled to fit the width of the view.
     */
    public void setIllustration(Drawable illustration) {
      if (illustration == this.illustration) {
        return;
      }
      this.illustration = illustration;
      invalidate();
      requestLayout();
    }
  
    /**
     * Set the aspect ratio reserved for the illustration. This overrides the top padding of the view
     * according to the width of this view and the aspect ratio. Children views will start being laid
     * out below this aspect ratio.
     *
     * @param aspectRatio A float value specifying the aspect ratio (= width / height). 0 to not
     *     override the top padding.
     */
    public void setAspectRatio(float aspectRatio) {
      this.aspectRatio = aspectRatio;
      invalidate();
      requestLayout();
    }
  
    @Override
    @Deprecated
    public void setForeground(Drawable d) {
      setIllustration(d);
    }
  
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
      if (aspectRatio != 0.0f) {
        int parentWidth = MeasureSpec.getSize(widthMeasureSpec);
        int illustrationHeight = (int) (parentWidth / aspectRatio);
        illustrationHeight = (int) (illustrationHeight - (illustrationHeight % baselineGridSize));
        setPadding(0, illustrationHeight, 0, 0);
      }
      if (VERSION.SDK_INT >= VERSION_CODES.LOLLIPOP) {
        //noinspection AndroidLintInlinedApi
        setOutlineProvider(ViewOutlineProvider.BOUNDS);
      }
      super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }
  
    @Override
    protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
      final int layoutWidth = right - left;
      final int layoutHeight = bottom - top;
      if (illustration != null) {
        int intrinsicWidth = illustration.getIntrinsicWidth();
        int intrinsicHeight = illustration.getIntrinsicHeight();
  
        viewBounds.set(0, 0, layoutWidth, layoutHeight);
        if (aspectRatio != 0f) {
          scale = layoutWidth / (float) intrinsicWidth;
          intrinsicWidth = layoutWidth;
          intrinsicHeight = (int) (intrinsicHeight * scale);
        }
        Gravity.apply(
            Gravity.FILL_HORIZONTAL | Gravity.TOP,
            intrinsicWidth,
            intrinsicHeight,
            viewBounds,
            illustrationBounds);
        illustration.setBounds(illustrationBounds);
      }
      if (background != null) {
        // Scale the background bounds by the same scale to compensate for the scale done to the
        // canvas in onDraw.
        background.setBounds(
            0,
            0,
            (int) Math.ceil(layoutWidth / scale),
            (int) Math.ceil((layoutHeight - illustrationBounds.height()) / scale));
      }
      super.onLayout(changed, left, top, right, bottom);
    }
  
    @Override
    public void onDraw(Canvas canvas) {
      if (background != null) {
        // Draw the background filling parts not covered by the illustration
        canvas.save();
        canvas.translate(0, illustrationBounds.height());
        // Scale the background so its size matches the foreground
        canvas.scale(scale, scale, 0, 0);
        if (VERSION.SDK_INT > VERSION_CODES.JELLY_BEAN_MR1
            && shouldMirrorDrawable(background, getLayoutDirection())) {
          // Flip the illustration for RTL layouts
          canvas.scale(-1, 1);
          canvas.translate(-background.getBounds().width(), 0);
        }
        background.draw(canvas);
        canvas.restore();
      }
      if (illustration != null) {
        canvas.save();
        if (VERSION.SDK_INT > VERSION_CODES.JELLY_BEAN_MR1
            && shouldMirrorDrawable(illustration, getLayoutDirection())) {
          // Flip the illustration for RTL layouts
          canvas.scale(-1, 1);
          canvas.translate(-illustrationBounds.width(), 0);
        }
        // Draw the illustration
        illustration.draw(canvas);
        canvas.restore();
      }
      super.onDraw(canvas);
    }
  
    private boolean shouldMirrorDrawable(Drawable drawable, int layoutDirection) {
      if (layoutDirection == LayoutDirection.RTL) {
        if (VERSION.SDK_INT >= VERSION_CODES.KITKAT) {
          return drawable.isAutoMirrored();
        } else if (VERSION.SDK_INT >= VERSION_CODES.JELLY_BEAN_MR1) {
          final int flags = getContext().getApplicationInfo().flags;
          //noinspection AndroidLintInlinedApi
          return (flags & ApplicationInfo.FLAG_SUPPORTS_RTL) != 0;
        }
      }
      return false;
    }
  }
  