ArrowDrawable.java

/*
 * The MIT License (MIT)
 * <p/>
 * Copyright (c) 2016 Douglas Nassif Roma Junior
 * <p/>
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * <p/>
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 * <p/>
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

package com.micabytes.gui;

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.Rect;
import android.graphics.drawable.ColorDrawable;
import android.support.annotation.ColorInt;

/**
 * ArrowDrawable
 * Created by douglas on 09/05/16.
 */
public class ArrowDrawable extends ColorDrawable {

  public static final int LEFT = 0, TOP = 1, RIGHT = 2, BOTTOM = 3, AUTO = 4;

  private final Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
  private final int mBackgroundColor;
  private Path mPath;
  private final int mDirection;

  ArrowDrawable(@ColorInt int foregroundColor, int direction) {
    this.mBackgroundColor = Color.TRANSPARENT;
    this.mPaint.setColor(foregroundColor);
    this.mDirection = direction;
  }

  @Override
  protected void onBoundsChange(Rect bounds) {
    super.onBoundsChange(bounds);
    updatePath(bounds);
  }

  private synchronized void updatePath(Rect bounds) {
    mPath = new Path();

    switch (mDirection) {
      case LEFT:
        mPath.moveTo(bounds.width(), bounds.height());
        mPath.lineTo(0, bounds.height() / 2);
        mPath.lineTo(bounds.width(), 0);
        mPath.lineTo(bounds.width(), bounds.height());
        break;
      case TOP:
        mPath.moveTo(0, bounds.height());
        mPath.lineTo(bounds.width() / 2, 0);
        mPath.lineTo(bounds.width(), bounds.height());
        mPath.lineTo(0, bounds.height());
        break;
      case RIGHT:
        mPath.moveTo(0, 0);
        mPath.lineTo(bounds.width(), bounds.height() / 2);
        mPath.lineTo(0, bounds.height());
        mPath.lineTo(0, 0);
        break;
      case BOTTOM:
        mPath.moveTo(0, 0);
        mPath.lineTo(bounds.width() / 2, bounds.height());
        mPath.lineTo(bounds.width(), 0);
        mPath.lineTo(0, 0);
        break;
    }

    mPath.close();
  }

  @Override
  public void draw(Canvas canvas) {
    canvas.drawColor(mBackgroundColor);
    if (mPath == null)
      updatePath(getBounds());
    canvas.drawPath(mPath, mPaint);
  }

  @Override
  public void setAlpha(int alpha) {
    mPaint.setAlpha(alpha);
  }

  public void setColor(@ColorInt int color) {
    mPaint.setColor(color);
  }

  @Override
  public void setColorFilter(ColorFilter colorFilter) {
    mPaint.setColorFilter(colorFilter);
  }

  @Override
  public int getOpacity() {
    if (mPaint.getColorFilter() != null) {
      return PixelFormat.TRANSLUCENT;
    }

    switch (mPaint.getColor() >>> 24) {
      case 255:
        return PixelFormat.OPAQUE;
      case 0:
        return PixelFormat.TRANSPARENT;
    }
    return PixelFormat.TRANSLUCENT;
  }
}