var frame_padding = 0;
var titlebar_h = 25;
var toolbar_h = 8;
var statusbar_h = 35;
var clientarea_margin = 0;

// preload button images to ensure un-delayed image swapping    
var button_down_outset = new Image();
var button_down_inset = new Image();
var button_up_outset = new Image();
var button_up_inset = new Image();
button_down_outset.src = 'button_down_outset.gif';
button_down_inset.src = 'button_down_inset.gif';
button_up_outset.src = 'button_up_outset.gif';
button_up_inset.src = 'button_up_inset.gif';

// to save window height when window is minimized
var last_window_h;


// initWindow() moves elements to their adequate locations
// and builds coherences between these elements by converting outer frame, client area and images for resize functionalities
// to 'childern' of the draggable titlebar 
function initWindow()
{
    dd.elements.titlebar.moveTo(dd.elements.frame.x+2+frame_padding, dd.elements.frame.y+2+frame_padding);
    dd.elements.titlebar.addChild("frame");
    dd.elements.titlebar.setZ(dd.elements.frame.z+1); // ensure that titlebar is floating above frame
    dd.elements.titlebar.resizeTo(dd.elements.frame.w-4-(frame_padding<<1), titlebar_h);

    dd.elements.clientarea.moveTo(dd.elements.frame.x+2+frame_padding+clientarea_margin, dd.elements.titlebar.y+titlebar_h+toolbar_h+clientarea_margin);
    dd.elements.titlebar.addChild("clientarea");
    dd.elements.clientarea.resizeTo(dd.elements.frame.w-4-(frame_padding<<1)-(clientarea_margin<<1), dd.elements.frame.h-titlebar_h-toolbar_h-statusbar_h-4-(frame_padding<<1)-clientarea_margin);

    dd.elements.resizehandle.moveTo(dd.elements.frame.x+dd.elements.frame.w-dd.elements.resizehandle.w-2, dd.elements.frame.y+dd.elements.frame.h-dd.elements.resizehandle.h-2);
    dd.elements.resizebutton.moveTo(dd.elements.titlebar.x+dd.elements.titlebar.w-dd.elements.resizebutton.w-frame_padding-(titlebar_h>>1)+Math.round(dd.elements.resizebutton.w/2), dd.elements.titlebar.y+Math.round(titlebar_h/2)-Math.round(dd.elements.resizebutton.h/2));
    dd.elements.titlebar.addChild("resizebutton");
    dd.elements.titlebar.addChild("resizehandle");
    
    dd.elements.titlebar.show();
}
initWindow();


// my_PickFunc, my_DragFunc and my_DropFunc override their namesakes in wz_dragdrop.js
function my_PickFunc()
{
    if (dd.obj.name == "resizebutton")
    {
        dd.obj.swapImage(dd.elements.clientarea.visible? button_up_inset.src : button_down_inset.src);
    }
}


function my_DragFunc()
{
    if (dd.obj.name == "resizehandle")
    {
        dd.elements.frame.resizeTo(dd.obj.x-dd.elements.frame.x+dd.obj.w+2, dd.obj.y-dd.elements.frame.y+dd.obj.h+2);
        dd.elements.titlebar.resizeTo(dd.obj.x-dd.elements.titlebar.x+dd.obj.w-frame_padding, titlebar_h);
        dd.elements.clientarea.resizeTo(dd.elements.frame.w-4-(frame_padding<<1)-(clientarea_margin<<1), dd.elements.frame.h-titlebar_h-toolbar_h-statusbar_h-4-(frame_padding<<1)-clientarea_margin);
        dd.elements.resizebutton.moveTo(dd.elements.titlebar.x+dd.elements.titlebar.w-dd.elements.resizebutton.w-frame_padding-(titlebar_h>>1)+Math.round(dd.elements.resizebutton.w/2), dd.elements.resizebutton.y);
    }
}


function my_DropFunc()
{
    if (dd.obj.name == "resizebutton")
    {
        if (dd.elements.clientarea.visible)
        {
            dd.obj.swapImage(button_down_outset.src);
            dd.elements.clientarea.hide();
            dd.elements.resizehandle.hide();
            last_window_h = dd.elements.frame.h;
            dd.elements.frame.resizeTo(dd.elements.frame.w, titlebar_h+(frame_padding<<1)+4);
        }
        else
        {
            dd.obj.swapImage(button_up_outset.src);
            dd.elements.clientarea.show();
            dd.elements.resizehandle.show();
            dd.elements.frame.resizeTo(dd.elements.frame.w, last_window_h);
        }
    }
}