CircleIndicator.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.Canvas;
import android.graphics.Paint;
import android.graphics.Paint.Style;
import android.util.AttributeSet;

public class CircleIndicator extends BaseIndicator {
    private static final int STYLE_STROKE = 0;

    private static final int STYLE_FILL = 1;

    private float radius = 3;

    private final Paint mPaintInactive = new Paint(Paint.ANTI_ALIAS_FLAG);

    private final Paint mPaintActive = new Paint(Paint.ANTI_ALIAS_FLAG);

    /**
     * @param context
     * @param attrs
     */
    public CircleIndicator(Context context, AttributeSet attrs) {
        super(context, attrs);
        TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.Indicator);
        int activeType = typedArray.getInt(R.styleable.Indicator_circleActiveType, STYLE_FILL);
        int activeDefaultColor = 0xFFFFFFFF;
        int activeColor = typedArray.getColor(R.styleable.Indicator_circleActiveColor, activeDefaultColor);
        int inactiveType = typedArray.getInt(R.styleable.Indicator_circleInactiveType, STYLE_FILL);
        int inactiveDefaultColor = 0x44FFFFFF;
        int inactiveColor = typedArray.getColor(R.styleable.Indicator_circleInactiveColor, inactiveDefaultColor);
        radius = typedArray.getDimension(R.styleable.Indicator_circleRadius, 3.0f);
        typedArray.recycle();
        switch (inactiveType) {
            case STYLE_FILL:
                mPaintInactive.setStyle(Style.FILL);
                break;
            default:
                mPaintInactive.setStyle(Style.STROKE);
        }
        mPaintInactive.setColor(inactiveColor);
        switch (activeType) {
            case STYLE_STROKE:
                mPaintActive.setStyle(Style.STROKE);
                break;
            default:
                mPaintActive.setStyle(Style.FILL);
        }
        mPaintActive.setColor(activeColor);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        float mLeft = getPaddingLeft() + radius;
        float mTop = getPaddingTop() + radius;
        float mInnerMargin = getInnerMargin() + 2 * radius;
        int index = getPosition();
        for (int i = 0; i < getViewFlow().getViewsCount(); i++) {
            if (i == index) {
                canvas.drawCircle(mLeft + mInnerMargin * index, mTop, radius, mPaintActive);
            } else {
                canvas.drawCircle(mLeft + mInnerMargin * i, mTop, radius, mPaintInactive);
            }
        }
    }

    @Override
    protected int onMeasureWidth(int measureSpec) {
        int specMode = MeasureSpec.getMode(measureSpec);
        int specSize = MeasureSpec.getSize(measureSpec);
        int width = specSize;
        if (specMode != MeasureSpec.EXACTLY) {
            int count = getViewFlow().getAdapter().getCount();
            width = (int) (getPaddingLeft() + getPaddingRight() + (count * 2 * radius) + (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) {
            height = (int) (2 * radius + getPaddingTop() + getPaddingBottom() + 1);
            if (specMode == MeasureSpec.AT_MOST) {
                height = Math.min(height, specSize);
            }
        }
        return height;
    }
}