/*
 * Copyright 2014 Chris Banes
 *
 * 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.cheikh.lazywaimai.widget;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.View;
import android.widget.LinearLayout;

class SlidingTabStrip extends LinearLayout {

    private static final int DEFAULT_INDICATOR_HEIGHT_DIPS = 4;

    private int mSelectedIndicatorHeight;
    private final Paint mSelectedIndicatorPaint;

    private int mSelectedPosition;
    private float mSelectionOffset;

    SlidingTabStrip(Context context) {
        this(context, null);
    }

    SlidingTabStrip(Context context, AttributeSet attrs) {
        super(context, attrs);
        setWillNotDraw(false);

        final float density = getResources().getDisplayMetrics().density;
        mSelectedIndicatorHeight = (int) (DEFAULT_INDICATOR_HEIGHT_DIPS * density);
        mSelectedIndicatorPaint = new Paint();
    }

    void setSelectedIndicatorColor(int color) {
        mSelectedIndicatorPaint.setColor(color);
        invalidate();
    }

    void setSelectedIndicatorHeight(int height) {
        mSelectedIndicatorHeight = height;
        invalidate();
    }

    void onViewPagerPageChanged(int position, float positionOffset) {
        mSelectedPosition = position;
        mSelectionOffset = positionOffset;
        invalidate();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        final int height = getHeight();
        final int childCount = getChildCount();

        // Thick colored underline below the current selection
        if (childCount > 0) {
            View selectedTitle = getChildAt(mSelectedPosition);
            int left = selectedTitle.getLeft();
            int right = selectedTitle.getRight();

            if (mSelectionOffset > 0f && mSelectedPosition < (getChildCount() - 1)) {
                // Draw the selection partway between the tabs
                View nextTitle = getChildAt(mSelectedPosition + 1);
                left = (int) (mSelectionOffset * nextTitle.getLeft() +
                        (1.0f - mSelectionOffset) * left);
                right = (int) (mSelectionOffset * nextTitle.getRight() +
                        (1.0f - mSelectionOffset) * right);
            }

            canvas.drawRect(left, height - mSelectedIndicatorHeight, right,
                    height, mSelectedIndicatorPaint);
        }
    }

}