CustomSlidePanelLayout.java

package net.avenwu.support.widget;


import android.annotation.TargetApi;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.os.Build;
import android.support.v4.widget.SlidingPaneLayout;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;

/**
 * Support level 11 and later;
 * TODO use nineolddroid for devices under level 11
 * <p/>
 * Created by chaobin on 2/18/15.
 */
@TargetApi(11)
public class CustomSlidePanelLayout extends SlidingPaneLayout implements SlidingPaneLayout.PanelSlideListener {
    protected View mMenuPanel;
    protected float mSlideOffset;
    protected boolean isCustomable = false;

    public CustomSlidePanelLayout(Context context) {
        this(context, null);
    }

    public CustomSlidePanelLayout(Context context, AttributeSet attrs) {
        this(context, attrs, -1);
    }

    public CustomSlidePanelLayout(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        if (isInEditMode()) return;
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
            isCustomable = true;
            super.setPanelSlideListener(this);
            setSliderFadeColor(0);
        }
    }

    @Override
    public void onPanelSlide(View panel, float slideOffset) {
        mSlideOffset = slideOffset;
        if (mMenuPanel == null) {
            final int childCount = getChildCount();
            for (int i = 0; i < childCount; i++) {
                final View child = getChildAt(i);
                if (child != panel) {
                    mMenuPanel = child;
                    break;
                }
            }
        }
        final float scaleLeft = 1 - 0.3f * (1 - slideOffset);
        mMenuPanel.setPivotX(-0.5f * mMenuPanel.getWidth());
        mMenuPanel.setPivotY(mMenuPanel.getHeight() / 2f);
        mMenuPanel.setScaleX(scaleLeft);
        mMenuPanel.setScaleY(scaleLeft);

        final float scale = 1 - 0.2f * slideOffset;
        panel.setPivotX(0);
        panel.setPivotY(panel.getHeight() / 2.0f);
        panel.setScaleX(scale);
        panel.setScaleY(scale);
        if (mListener != null) {
            mListener.onPanelSlide(panel, slideOffset);
        }
    }

    @Override
    public void onPanelOpened(View panel) {
        if (mListener != null) {
            mListener.onPanelOpened(panel);
        }
    }

    @Override
    public void onPanelClosed(View panel) {
        if (mListener != null) {
            mListener.onPanelClosed(panel);
        }
    }

    PanelSlideListener mListener;

    @Override
    public void setPanelSlideListener(PanelSlideListener listener) {
        if (isCustomable) {
            mListener = listener;
        } else {
            super.setPanelSlideListener(listener);
        }
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        if (isCustomable) {
            dimOnForeground(canvas);
        }
    }

    @Override
    protected boolean drawChild(Canvas canvas, View child, long drawingTime) {
        boolean result = super.drawChild(canvas, child, drawingTime);
        if (isCustomable && child == mMenuPanel) {
            dimOnForeground(canvas);
        }
        return result;
    }

    /**
     * dim the view
     *
     * @param canvas
     */
    private void dimOnForeground(Canvas canvas) {
        canvas.drawColor(Color.argb((int) (0xff * (1 - mSlideOffset)), 0, 0, 0));
    }

    private boolean mSlideEnable = true;

    public void setSlideEnable(boolean slideEnable) {
        mSlideEnable = slideEnable;
    }

    @Override
    public boolean onInterceptTouchEvent(MotionEvent ev) {
        return mSlideEnable && super.onInterceptTouchEvent(ev);
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {
        return mSlideEnable && super.onTouchEvent(ev);
    }
}