com.jakewharton.behavior.drawer.DrawerBehavior.java Source code

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Here is the source code for com.jakewharton.behavior.drawer.DrawerBehavior.java

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/*
 * Copyright 2016 Jake Wharton
 *
 * 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.jakewharton.behavior.drawer;

import android.content.Context;
import android.content.res.TypedArray;
import android.support.annotation.Keep;
import android.support.design.widget.CoordinatorLayout;
import android.support.v4.util.SimpleArrayMap;
import android.support.v4.view.GravityCompat;
import android.util.AttributeSet;
import android.view.Gravity;
import android.view.MotionEvent;
import android.view.View;

public final class DrawerBehavior extends CoordinatorLayout.Behavior<View> {
    private static void validateGravity(int gravity) {
        if (gravity != Gravity.LEFT && gravity != Gravity.RIGHT && gravity != GravityCompat.START
                && gravity != GravityCompat.END) {
            throw new IllegalArgumentException("Only START, END, LEFT, or RIGHT gravity is supported.");
        }
    }

    private final SimpleArrayMap<View, BehaviorDelegate> delegates = new SimpleArrayMap<>();
    private final int gravity;

    @SuppressWarnings("unused") // Public API for programmatic instantiation.
    public DrawerBehavior(int gravity) {
        validateGravity(gravity);
        this.gravity = gravity;
    }

    @Keep
    @SuppressWarnings("unused") // Instantiated reflectively from layout XML.
    public DrawerBehavior(Context context, AttributeSet attrs) {
        super(context, attrs);
        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.DrawerBehavior);
        int gravity = a.getInteger(R.styleable.DrawerBehavior_android_layout_gravity, GravityCompat.END);
        a.recycle();

        validateGravity(gravity);
        this.gravity = gravity;
    }

    private BehaviorDelegate delegate(CoordinatorLayout parent, View child) {
        BehaviorDelegate delegate = delegates.get(child);
        if (delegate == null) {
            delegate = new BehaviorDelegate(parent, child, gravity);
            delegates.put(child, delegate);
        }
        return delegate;
    }

    @Override
    public boolean onLayoutChild(CoordinatorLayout parent, View child, int layoutDirection) {
        return child.getVisibility() == View.GONE //
                || delegate(parent, child).onLayoutChild();
    }

    @Override
    public boolean onInterceptTouchEvent(CoordinatorLayout parent, View child, MotionEvent ev) {
        return delegate(parent, child).onInterceptTouchEvent(ev);
    }

    @Override
    public boolean onTouchEvent(CoordinatorLayout parent, View child, MotionEvent ev) {
        return delegate(parent, child).onTouchEvent(ev);
    }
}