BitmapIndicator.java

/**
 * Copyright (c) 2013-2014, Rinc Liu (http://rincliu.com).
 *
 * 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.rincliu.library.widget.viewflow;

import com.rincliu.library.R;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.drawable.BitmapDrawable;
import android.util.AttributeSet;

public class BitmapIndicator extends BaseIndicator {
    private final Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);

    private Bitmap activeBitmap, inactiveBitmap;

    /**
     * @param context
     * @param attrs
     */
    public BitmapIndicator(Context context, AttributeSet attrs) {
        super(context, attrs);
        TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.Indicator);
        try {
            activeBitmap = ((BitmapDrawable) typedArray.getDrawable(R.styleable.Indicator_bitmapActive)).getBitmap();
        } catch (Exception e) {
            throw new IllegalArgumentException("ActiveBitmap should be a BitmapDrawable object.");
        }
        try {
            inactiveBitmap = ((BitmapDrawable) typedArray.getDrawable(R.styleable.Indicator_bitmapInactive)).getBitmap();
        } catch (Exception e) {
            throw new IllegalArgumentException("InactiveBitmap should be a BitmapDrawable object.");
        }
        typedArray.recycle();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        if (activeBitmap != null && inactiveBitmap != null) {
            int index = getPosition();
            for (int i = 0; i < getViewFlow().getViewsCount(); i++) {
                if (i == index) {
                    canvas.drawBitmap(activeBitmap, getPaddingLeft() + (getInnerMargin() + activeBitmap.getWidth())
                            * index, getPaddingTop(), mPaint);
                } else {
                    canvas.drawBitmap(inactiveBitmap, getPaddingLeft() + (getInnerMargin() + inactiveBitmap.getWidth())
                            * i, getPaddingTop(), mPaint);
                }
            }

        }
    }

    @Override
    protected int onMeasureWidth(int measureSpec) {
        int specMode = MeasureSpec.getMode(measureSpec);
        int specSize = MeasureSpec.getSize(measureSpec);
        int width = specSize;
        if (specMode != MeasureSpec.EXACTLY) {
            if (activeBitmap != null && inactiveBitmap != null) {
                int count = getViewFlow().getAdapter().getCount();
                width = (int) (getPaddingLeft() + getPaddingRight()
                        + (count * Math.max(activeBitmap.getWidth(), inactiveBitmap.getWidth())) + (count - 1)
                        * getInnerMargin() + 1);
            }
            if (specMode == MeasureSpec.AT_MOST) {
                width = Math.min(width, specSize);
            }
        }
        return width;
    }

    @Override
    protected int onMeasureHeight(int measureSpec) {
        int specMode = MeasureSpec.getMode(measureSpec);
        int specSize = MeasureSpec.getSize(measureSpec);
        int height = specSize;
        if (specMode != MeasureSpec.EXACTLY) {
            if (activeBitmap != null && inactiveBitmap != null) {
                height = (int) (Math.max(activeBitmap.getHeight(), inactiveBitmap.getHeight()) + getPaddingTop()
                        + getPaddingBottom() + 1);
            }
            if (specMode == MeasureSpec.AT_MOST) {
                height = Math.min(height, specSize);
            }
        }
        return height;
    }
}