ancestor_input_clipper.js

(function(property) {

    var local = new Phaser.Point();
    function askAncestors( child, pointer ) {
        for ( var parent = child.parent; parent; parent = parent.parent ) {
            var clip = parent[property];
            if ( !clip ) continue;
            parent.game.input.getLocalPosition( parent, pointer, local);
            var cx = local.x - clip.x, cy = local.y - clip.y;
            return (0 <= cx) && (cx < clip.width) && (0 <= cy) && (cy < clip.height);
        }
        return true;
    }

    var _checkPointerDown_ = Phaser.InputHandler.prototype.checkPointerDown;
    Phaser.InputHandler.prototype.checkPointerDown = function(pointer, fastTest) {
        if ( !_checkPointerDown_.call( this, pointer, fastTest ) ) return false;
        return askAncestors( this.sprite, pointer );
    }

    var _checkPointerOver_ = Phaser.InputHandler.prototype.checkPointerOver;
    Phaser.InputHandler.prototype.checkPointerOver = function(pointer, fastTest) {
        if ( !_checkPointerOver_.call( this, pointer, fastTest ) ) return false;
        return askAncestors( this.sprite, pointer );
    }

})( 'input_clipping_rect' );

Phaser.InputHandler extension to perform child input clipping, a bubbling event system would be better but this is a quick way to provide a way for ancestors to reject input for a child.