Managing the User Interface and Controlling the Application

As the overview diagram shows, the root object of the IQL object model is McApplication. This object exposes most other IQL objects through its properties and methods but also allows you to control the application's User Interface to do such things as displaying information in various ways, displaying Dialogs, changing menus and toolbars, loading and saving settings, responding to Application events, or managing collections of objects like Identities and Projects.

The ObjectModelIntro.iqp VBA project can be loaded in IQstudio to test some of the following examples as well as others.

Displaying Information

The Application can be used to display diagnostic information such as in the following example:

' Name is the default property

MsgBox Application

' Simple output and formating

Debug.Print Name & " is installed in " & Path

Or use the Output window and the status bar for more advanced output:

' First make sure the output window is visible, select "Output" page

Output.Show "Output"

' Clear the default page and make the font bigger and bold

Output.Clear

Output.Font.Bold = True

Output.Font.Size = 20

' Print the image size in the output window (which is the default page)

Output.PrintMessage ActiveImage.DisplayName & " is " & ActiveImage.Width & "x" & ActiveImage.Height

' Also display the name in the first status pane

StatusBar.Panes(0).Caption = ActiveImage.DisplayName

Controlling the Application visibility

Simple Application properties like Visible or FullScreen are used to control the visibility of the Application window:

' This is important when the application is started by automation

Application.Visible = True

' Switch to full screen mode

FullScreen = True

' Wait for user input

While MsgBox("Are we done?", vbYesNo) <> vbYes

Wend

' End full screen mode

FullScreen = False

The VBA window is also accessible to user macros:

' Use the VBE object model to display the VBA IDE

VBE.MainWindow.Visible = True

Displaying Dialogs

The Dialogs collection allows to control all the tool dialogs and their pages. User defined dialogs can also be created as explained in the Creating Dialogs section.

' Use the dialog collection to show the contrast dialog

Application.Dialogs("Contrast").Show

Controlling menus and toolbars

Menus and toolbars are exposed in the object model through the McCommandBars collection. This set of objects gives access to menu entries and toolbar buttons like in the following 2 examples.

' Use the CommandBars collection to hide the annotations toolbar

Application.CommandBars("Annotation").Visible = False

' Use the CommandBars collection to disable the Save command

Application.CommandBars("MenuBar").Controls("File").Controls("Save").Enabled = False

Loading and Saving Settings

The McSettings object exposed as Settings in the Application allows to associate persistent information with the current identity. Most tools use this capability to adapt their dialogs to user preferences.

' Settings can store any variable type: store an array

Settings.Set "MySetting", Array(1, 2, 3, 4)

' Use McToText to display the values

MsgBox McToText( Settings.Get("MySetting") )

Handling Application Events

The Application behavior can be controlled by monitoring its events like in the following piece of VBA code which could be pasted into the ThisSession module in the VBA editor.

'  Respond to Shutdown event by prompting the user to confirm

Private Sub McApplication_BeforeShutdown(Cancel As Boolean)

   ' Ask the user to confirm

   If MsgBox("Are you sure?", vbYesNo) <> vbYes Then

      Cancel = True

   End If

End Sub  

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