Statusbar, Windows, and Centering a Child Window

I have a project that I am working on where a popup window will appear asking for some parameters and then it will kick off a process which may take a while to return. The information on creating a new window, and centering it isn’t readily available, so I thought I’d do a posting on some of the testing code that I have written which will end up added to the project.

So, first off, I want to spawn a window that is in the Smart Office Style – this needs to be a modaldialog box – the user should be bound and focused only on MY script 😉

Then I want to add a standard status bar so we can provide updates on the progress of our long running process. I wanted the Close/Previous and Next buttons and I wanted to center the pop up on the existing window it was launched from.

You’d think that none of these things would be terribly difficult 🙂

Retrieving the Parent Window Position

Access to the window comes via the Host property on the controller object that is passed to the Init() method. It doesn’t give us a Window object, nor does it given us the EmbeddedHostWindow object, however it does give us access to a number of functions which will allow us to get what we need.

We can retrieve our Windows Width and Height directly from controller.Host.Width and controller.Host.Height

However getting the actual left and top positions of the window proved to be more challenging. I ended up using a tool called WPF Inspector and after some investigation I discovered that the position is determined by the Margins, not the Left and Top properties

But this presented another issue. None of the Host properties provide a direct path to the EmbeddedHostWindow so we can then retrieve the Margins.

It turned out that the controller.Host.VisualElement.Name property was “PART_Window” that we can see in the screenshot above – this meant that the VisualElement was a child of the EmbeddedHostWindow

So, we can use the VisualTreeHelper.GetParent() method to go up a level. As we are probably entering in to a world that is subject to change, in my code I actually run a loop iterating up the tree until I find an EmbeddedHostWindow.

Now that we have the EmbeddedHostWindow we can extract the margin values and save those for later analysis.

If you have a better way to achieve the same results, feel free to use the comments section!

Setting Our Child Windows Position

Now really, how difficult…oh wait, we’ve asked that question already 🙂

So we use the controller.Host.CreateDialog() function to create our new window, and we assign values to the .Left and .Top properties – however when we do a .ShowDialog() the values are totally ignored. <sigh>…

We can change this by subscribing to the Window.Loaded() event, and then set our .Left and .Top values there.

StatusBar and the Standard Close, Previous, Next buttons

These ones I’ve already done most of the leg work on in my SDK projects. The StatusBar is under the Mango.UI.Controls namespace and the standard Close, Previous and Next buttons are from the Mango.DesignSystem namespace.

The code will give you an idea of how to use them. I did have to hard-code the height of the Previous – I couldn’t find anything that would define the standard width when it didn’t have an icon so I had a look at the width of one of the existing previous buttons.

The Code


import System;
import System.Windows;
import System.Windows.Controls;
import MForms;

import Mango.UI.Controls;
import System.Windows.Media;

import Mango.DesignSystem;
import Mango.UI;

package MForms.JScript
	class testStatusBar
		var gdbgDebug;
		var gctController;
		// this is the host object that represents our child window
		var gihChildWindowInstanceHost;
		var gdblParentWindowLeft : double = 700;
		var gdblParentWindowTop : double = 200;
		var gdblParentWindowWidth : double = 0;
		var gdblParentWindowHeight : double = 0;
		var gtibCloseButton : ThemeIconButton;
		var gtibNextButton : ThemeIconButton;
		var gtibPreviousButton : ThemeIconButton;
		public function Init(element: Object, args: Object, controller : Object, debug : Object)
			var content : Object = controller.RenderEngine.Content;
			gdbgDebug = debug;
			gctController = controller;
			gdblParentWindowWidth = gctController.Host.Width;
			gdblParentWindowHeight = gctController.Host.Height;
				// how well supported this is, is well questionable
				// so lets wrap it in a try..catch() so we can
				// always go back to the default position values
				if(null != gctController.Host.VisualElement)
					// get the parent of the visual element, in ISO this ends
					// up being what we want, however this may change
					var actualWindow = VisualTreeHelper.GetParent(gctController.Host.VisualElement);
					// lets iterate up the tree until we have the EmbeddedHostWindow
					while((null != actualWindow) && (actualWindow.GetType().ToString() != "Mango.UI.Services.EmbeddedHostWindow"))
						actualWindow = VisualTreeHelper.GetParent(actualWindow);

					if(null != actualWindow)
						// we'll cast to the actual real object
						var ehwEmbeddedHostWindow : Mango.UI.Services.EmbeddedHostWindow = actualWindow;
						gdbgDebug.WriteLine("actualWindow = " + ehwEmbeddedHostWindow.GetType());
						// verify it has a margin property (it uses the margin and now the
						// left,top)
						if(null != ehwEmbeddedHostWindow.Margin)
							gdbgDebug.WriteLine("ehwEmbeddedHostWindow.Margin.Left = " + ehwEmbeddedHostWindow.Margin.Left);
							gdbgDebug.WriteLine("ehwEmbeddedHostWindow.Margin.Top = " + ehwEmbeddedHostWindow.Margin.Top);
							// make sure that we actually have values...I'm deliberately using >= 1 as we are using
							// doubles and we all know about doubles!
							if((ehwEmbeddedHostWindow.Margin.Left >= 1) && (ehwEmbeddedHostWindow.Margin.Top >= 1))
								// save our position for later manipulation
								gdblParentWindowLeft = ehwEmbeddedHostWindow.Margin.Left;
								gdblParentWindowTop = ehwEmbeddedHostWindow.Margin.Top;
				gdbgDebug.WriteLine("Failed to retrieve the parent windows positions, we will rely on the defaults.  " + ex);

			gdbgDebug.WriteLine("Width = " + gctController.Host.Width);
			gdbgDebug.WriteLine("Height = " + gctController.Host.Height);
		// create our window, we're also going to create a statusbar
		// we want to be able to position our window rather than
		// rely on the rather random default windows positioning
		private function createSimulateWindow(astrWindowTitle : String)
			// first we need to create our Smart Office window
			gihChildWindowInstanceHost = gctController.Host.CreateDialog();
			gihChildWindowInstanceHost.Width = 400;
			gihChildWindowInstanceHost.Height = 200;
			// set the title that appears
			gihChildWindowInstanceHost.HostTitle = astrWindowTitle;
			// set up a grid which will be used to display our content
			// in the body of the email
			var gdGrid : Grid = new Grid();
			gdGrid.MinWidth = 300;
			gdGrid.MinHeight = 150;
			gdGrid.VerticalAlignment = VerticalAlignment.Stretch;
			gdGrid.HorizontalAlignment = HorizontalAlignment.Stretch;

			// originally I had been using WindowContent - which wiped out the
			// title, then I discovered the HostContent property
			// which is the body of the window
			gihChildWindowInstanceHost.HostContent = gdGrid;
			// we want a status bar so we look like a REAL window
			var stsBar : StatusBar = new StatusBar();
			stsBar.HorizontalAlignment = HorizontalAlignment.Stretch;
			stsBar.VerticalAlignment = VerticalAlignment.Bottom;
			// add the Status bar to the grid
			// add a message to the status bar, there is also a method to 
			// make the message timeout and disappear
			stsBar.AddMessage("My Statusbar");
			// add the standard Next/Previous/Close buttons
			gtibNextButton = new ThemeIconButton();
			gtibNextButton.IconName = "Next";
			gtibNextButton.Content = "Next";
			gtibNextButton.IconAlignment= HorizontalAlignment.Right;
			gtibNextButton.IsPrimary = true;
			gtibNextButton.VerticalAlignment = VerticalAlignment.Bottom;
			gtibNextButton.HorizontalAlignment = HorizontalAlignment.Right;
			gtibNextButton.Margin = new Thickness(0, 0, Margins.Medium, Margins.Small + 20);

			var gtibPreviousButton : ThemeIconButton = new ThemeIconButton();
			gtibPreviousButton.IconName = "Previous";
			gtibPreviousButton.IconAlignment= HorizontalAlignment.Right;
			gtibPreviousButton.IsPrimary = false;
			gtibPreviousButton.VerticalAlignment = VerticalAlignment.Bottom;
			gtibPreviousButton.HorizontalAlignment = HorizontalAlignment.Right;
			gtibPreviousButton.Margin = new Thickness(0, 0, 80 + (Margins.Medium*2), Margins.Small + 20);
			// I had to retrieve this value from an existing previous control
			gtibPreviousButton.Width = 40;

			gtibCloseButton = new ThemeIconButton();
			gtibCloseButton.IconName = "Close";
			gtibCloseButton.Content = "Close";
			gtibCloseButton.IconAlignment= HorizontalAlignment.Left;
			gtibCloseButton.IsPrimary = false;
			gtibCloseButton.VerticalAlignment = VerticalAlignment.Bottom;
			gtibCloseButton.HorizontalAlignment = HorizontalAlignment.Left;
			gtibCloseButton.Margin = new Thickness(Margins.Medium, 0, 0, Margins.Small + 20);

			// add the Requested Event so we can clean up our script
			// because we want to position our window
			// we need to modify the Left and Top properties
			// when we get the Loaded event
			// finally, show our dialog box
		private function OnCloseClicked(sender : Object, e : RoutedEventArgs)
			ConfirmDialog.ShowInformationDialog("Close/Previous Clicked");

		private function OnNextClicked(sender : Object, e : RoutedEventArgs)
			ConfirmDialog.ShowInformationDialog("Next Clicked");
		public function OnRequested(sender : Object, e : RequestEventArgs)
			// be a good Smart Office Citizen and remove our requests
		public function OnLoaded(sender : Object, e : RoutedEventArgs)
			// here we are going to calculate the middle of the parent window
			// that is assuming that our own window isn't wider than the parent
			if(gdblParentWindowWidth > gihChildWindowInstanceHost.Width)
				gdblParentWindowLeft += ((gdblParentWindowWidth - gihChildWindowInstanceHost.Width) / 2);
			// here we are going to calculate the middle of the parent window
			// that is assuming that our own window isn't higher than the parent
			if(gdblParentWindowHeight > gihChildWindowInstanceHost.Height)
				gdblParentWindowTop += ((gdblParentWindowHeight - gihChildWindowInstanceHost.Height) / 2);
			// now set the specific location on the screen
			gihChildWindowInstanceHost.Left = gdblParentWindowLeft;
			gihChildWindowInstanceHost.Top = gdblParentWindowTop;


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One Response to Statusbar, Windows, and Centering a Child Window

  1. Salem says:

    Hi. Thank you for your code 🙂
    Can we access to Show History of the statusBar (with clic like a standard MFORMS) ?

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