MorphDrawable.java

/*
 * Copyright 2015 Google Inc.
 *
 * 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 io.plaidapp.ui.drawable;

import android.graphics.Canvas;
import android.graphics.ColorFilter;
import android.graphics.Outline;
import android.graphics.Paint;
import android.graphics.PixelFormat;
import android.graphics.drawable.Drawable;
import android.support.annotation.ColorInt;
import android.support.annotation.NonNull;
import android.util.Property;

import io.plaidapp.util.AnimUtils;

/**
 * A drawable that can morph size, shape (via it's corner radius) and color.  Specifically this is
 * useful for animating between a FAB and a dialog.
 */
public class MorphDrawable extends Drawable {

    public static final Property CORNER_RADIUS
            = AnimUtils.createFloatProperty(new AnimUtils.FloatProp<MorphDrawable>("cornerRadius") {
                @Override
                public void set(MorphDrawable morphDrawable, float value) {
                    morphDrawable.setCornerRadius(value);
                }

                @Override
                public float get(MorphDrawable morphDrawable) {
                    return morphDrawable.getCornerRadius();
                }
            });

    public static final Property<MorphDrawable, Integer> COLOR
            = AnimUtils.createIntProperty(new AnimUtils.IntProp<MorphDrawable>("color") {
                @Override
                public void set(MorphDrawable morphDrawable, int color) {
                    morphDrawable.setColor(color);
                }

                @Override
                public int get(MorphDrawable morphDrawable) {
                    return morphDrawable.getColor();
                }
            });

    private Paint paint;
    private float cornerRadius;

    public MorphDrawable(@ColorInt int color, float cornerRadius) {
        this.cornerRadius = cornerRadius;
        paint = new Paint(Paint.ANTI_ALIAS_FLAG);
        paint.setColor(color);
    }

    float getCornerRadius() {
        return cornerRadius;
    }

    void setCornerRadius(float cornerRadius) {
        this.cornerRadius = cornerRadius;
        invalidateSelf();
    }

    public int getColor() {
        return paint.getColor();
    }

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

    @Override
    public void draw(@NonNull Canvas canvas) {
        canvas.drawRoundRect(
                getBounds().left,
                getBounds().top,
                getBounds().right,
                getBounds().bottom,
                cornerRadius,
                cornerRadius,
                paint);
    }

    @Override
    public void getOutline(@NonNull Outline outline) {
        outline.setRoundRect(getBounds(), cornerRadius);
    }

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

    @Override
    public void setColorFilter(ColorFilter cf) {
        paint.setColorFilter(cf);
        invalidateSelf();
    }

    @Override
    public int getOpacity() {
        return paint.getAlpha() == 255 ? PixelFormat.OPAQUE : PixelFormat.TRANSLUCENT;
    }

}