Measure 核心代码块之一

/** 
 * Figures out the measure spec for the root view in a window based on it's 
 * layout params. 
 * 
 * @param windowSize 
 *            The available width or height of the window 
 * 
 * @param rootDimension 
 *            The layout params for one dimension (width or height) of the 
 *            window. 
 * 
 * @return The measure spec to use to measure the root view. 
 */  
private int getRootMeasureSpec(int windowSize, int rootDimension) {  
    int measureSpec;  
    switch (rootDimension) {  

    case ViewGroup.LayoutParams.FILL_PARENT:  
        // Window can't resize. Force root view to be windowSize.  
        measureSpec = MeasureSpec.makeMeasureSpec(windowSize, MeasureSpec.EXACTLY);  
        break;  
    case ViewGroup.LayoutParams.WRAP_CONTENT:  
        // Window can resize. Set max size for root view.  
        measureSpec = MeasureSpec.makeMeasureSpec(windowSize, MeasureSpec.AT_MOST);  
        break;  
    default:  
        // Window wants to be an exact size. Force root view to be that size.  
        measureSpec = MeasureSpec.makeMeasureSpec(rootDimension, MeasureSpec.EXACTLY);  
        break;  
    }  
    return measureSpec;  
}  

The issue only provides the getRootMeasureSpec method and does not name a file, test, or requested change. Start by identifying the surrounding Android source and clarifying whether this snippet is intended as blog documentation; completion cannot be defined until the expected documentation or correction is specified.