XRelativeLayoutForSoftkeyDetect.java

/*
 This file was modified from or inspired by Apache Cordova.

 Licensed to the Apache Software Foundation (ASF) under one
 or more contributor license agreements. See the NOTICE file
 distributed with this work for additional information
 regarding copyright ownership. The ASF licenses this file
 to you 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.polyvi.xface;

import org.apache.cordova.LOG;

import com.polyvi.xface.core.XISystemContext;

import android.content.Context;
import android.widget.RelativeLayout;

/**
 * 继承RelativeLayout，通过重写onMeasure去检查view的高度变化，用于检测软键盘是否弹出。
 * */
public class XRelativeLayoutForSoftkeyDetect extends RelativeLayout {

	 private static final String TAG = "SoftKeyboardDetect";

	    private int oldHeight = 0;  // Need to save the old height as not to send redundant events
	    private int oldWidth = 0; // Need to save old width for orientation change
	    private int screenWidth = 0;
	    private int screenHeight = 0;
	    private XISystemContext app = null;

	    public XRelativeLayoutForSoftkeyDetect(Context context, int width, int height) {
	        super(context);
	        screenWidth = width;
	        screenHeight = height;
	        app = (XISystemContext) context;
	    }

	    @Override
	    /**
	     * Start listening to new measurement events.  Fire events when the height
	     * gets smaller fire a show keyboard event and when height gets bigger fire
	     * a hide keyboard event.
	     *
	     * Note: We are using app.postMessage so that this is more compatible with the API
	     *
	     * @param widthMeasureSpec
	     * @param heightMeasureSpec
	     */
	    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
	        super.onMeasure(widthMeasureSpec, heightMeasureSpec);

	        LOG.v(TAG, "We are in our onMeasure method");

	        // Get the current height of the visible part of the screen.
	        // This height will not included the status bar.\
	        int width, height;

	        height = MeasureSpec.getSize(heightMeasureSpec);
	        width = MeasureSpec.getSize(widthMeasureSpec);
	        LOG.v(TAG, "Old Height = %d", oldHeight);
	        LOG.v(TAG, "Height = %d", height);
	        LOG.v(TAG, "Old Width = %d", oldWidth);
	        LOG.v(TAG, "Width = %d", width);

	        // If the oldHeight = 0 then this is the first measure event as the app starts up.
	        // If oldHeight == height then we got a measurement change that doesn't affect us.
	        if (oldHeight == 0 || oldHeight == height) {
	            LOG.d(TAG, "Ignore this event");
	        }
	        // Account for orientation change and ignore this event/Fire orientation change
	        else if (screenHeight == width)
	        {
	            int tmp_var = screenHeight;
	            screenHeight = screenWidth;
	            screenWidth = tmp_var;
	            LOG.v(TAG, "Orientation Change");
	        }
	        // If the height as gotten bigger then we will assume the soft keyboard has
	        // gone away.
	        else if (height > oldHeight) {
	            if (app != null)
	                app.getCurAppView().sendJavascript("cordova.fireDocumentEvent('hidekeyboard');");
	        }
	        // If the height as gotten smaller then we will assume the soft keyboard has 
	        // been displayed.
	        else if (height < oldHeight) {
	            if (app != null)
	            	 app.getCurAppView().sendJavascript("cordova.fireDocumentEvent('showkeyboard');");
	        }

	        // Update the old height for the next event
	        oldHeight = height;
	        oldWidth = width;
	    }

}