VisibleBounds

[Jeff Martin]

Below is my poor man's getVisibleBounds. I'm using this so that my custom text pane only needs to add child nodes for lines of text that are visible - similar to how ListView and friends only add cell nodes for visible items. I hope I'm on the right track - I was surprised that my web search for getVisibleBounds() came up so empty. If nobody points out my idiocy, I'm going to put this in a blog.

jeff

/**
 * Returns the visible bounds for a node based on ancestor clips (or null if no clipping found).
 */
public static Bounds getVisibleBounds(Node aNode)
{
    // Get parent visible bounds (if set, convert to local)
    Bounds bounds = aNode.getParent()!=null? getVisibleBounds(aNode.getParent()) : null;
    if(bounds!=null) { if(!bounds.isEmpty()) bounds = aNode.parentToLocal(bounds); else return bounds; }
    
    // If node has clip, get clip local bounds (intersected with parent visible bounds if present)
    if(aNode.getClip()!=null) { Node clip = aNode.getClip(); Bounds cb = clip.getBoundsInLocal();
        bounds = bounds!=null? getIntersectingBounds(cb, bounds) : cb; }
    
    // Return node visible bounds
    return bounds;
}

/**
 * Returns the intersection bounds of two bounds.
 */
public static Bounds getIntersectingBounds(Bounds b1, Bounds b2)
{
    if(!b1.intersects(b2)) return new BoundingBox(0,0,-1,-1);
    double minx = Math.max(b1.getMinX(), b2.getMinX());
    double miny = Math.max(b1.getMinY(), b2.getMinY());
    double maxx = Math.min(b1.getMaxX(), b2.getMaxX());
    double maxy = Math.min(b1.getMaxY(), b2.getMaxY());
    return new BoundingBox(minx, miny, maxx-minx, maxy-miny);
}


On Jun 10, 2014, at 6:59 PM, Jeff Martin <jeff at reportmill.com> wrote:

> What is the JFX equivalent of JComponent.getVisibleRect() - and is there a way to get a notification when it changes?
> 
> jeff