SetupControls is a method used to configure / initialize controls and content on the emulated task dialog. Values from the TTaskDialog owner are copied to the dialog form, including:

• Buttons
• CommonButtons
• RadioButtons
• Caption (application title or main form caption when omitted)
• Title (or the IconMessage when omitted)
• Text
• ExpandButtonCaption
• CollapseButtonCaption
• ExpandedText
• FooterText
• VerificationText

Values from the Flags property in TTaskDIalog are used to determine which content and UI elements are enabled on the dialog form.

SetupControls calls private method in the class to layout and align the elements on the dialog form. This includes setting the border style, border icons, and position for the dialog form. The font typeface and size used on the dialog are assigned in the method.

It creates and populates three (3) panels with the controls needed for the dialog. The top panel holds the main icon, title, text, and expanded text. The middle panel contains any radio buttons, command link buttons, query controls, or the progress bar for the dialog. The bottom panel contains the remainder of the controls on the dialog form including the expand /collapse button, verification check box, and footer text.

A timer enabled for the form is created, initialized, and started in the method.

SetupControls calculates the width needed for the dialog form. It uses the length of common elements (like Title, Text, and the cumlative length for button captions) when an explict Width has not been assigned for the task dialog. A minimum width of 120 pixels is assumed, but common calculated widths include 300, 420, amd 480 pixels. A minimum height of 200 pixels is assumed.

SetupControls is called from the Execute method before the ShowModal method is called for the emulated task dialog.

KeyDown is an overridden method in TLCLTaskDialog which implements the handler routine for OnKeyDown events in the dialog form. KeyDown ensures that Esc, Alt+F4, and F1 key down events are applied properly for the emulated task dialog.

When BorderIcons indicates that the dialog form can be closed (contains biSystemMenu), the Esc (Escape) key can be used to close the dialog form by calling the Close method. Without the system border icon, the Esc key is not handled in the method.

When Key and Shift indicate that the Alt+F4 key was pressed, the value in Key is digested (set to 0). The native task dialog blocks Alt+F4 to close the dialog, so it is blocked in the emulated task dialog as well.

When Key indicates that F1 was pressed, the DoOnHelp method in the TTaskDialog instance is called to signal an assigned OnHelp event handler in the task dialog. The value in Key is set to 0 to consume the key event.

KeyDown calls the inherited method prior to exit.

CreateNew is an overridden constructor in TLCLTaskDialog. It is the alternate constructor called when creating a form instance which does not have an associated resource file (.lfm). It extends the inherited method to assign the value in AOwner to the internal TTaskDialog member for the class instance.

CreateNew calls the inherited method to configure and initialize the dialog form instance. It sets the default values for internal members and properties like KeyPreview (True).

Destroy is the overridden destructor for the class instance. It ensures that the OnDialogDestroyed event handler in the TCustomTaskDialog instance for the dialog form is signalled (when assigned). Destroy calls the inherited destructor (in TCustomForm) prior to exit.

AfterConstruction is an overridden method in TLCLTaskDialog used to perform actions needed when the emulated dialog form instance has been created. It calls the inherited method on entry to set the bounds for the form, signal the OnCreate event handler (when assigned), and to perform scaling when enabled in both the application and the form.

Use the OnDialogConstructed event handler in the TTaskDialog instance to perform actions needed when the Handle for the dialog form has been realized.

DoShow is an overridden method in TLCLTaskDialog used to perform actions needed when the task dialog form is displayed for the first time. DoShow is called when queued OnResize or OnChangeBounds event handlers are executed, or when the Showing property is set to True.

DoShow calls the inherited method on entry to signal the OnShow event handler (when assigned). It ensures that the Handle for the task dialog form is allocated before any dialog-specific event handlers are signalled, like OnDialogConstructed or OnDialogCreated.

Execute is an Integer function used to configure, display, and capture the modal result value for the emulated task dialog. The return value contains the modal result for the button used to close the dialog form. No actions are performed in the method when the Owner of the form has not been assigned or is not a TTaskDialog instance. In this situation, the return value is -1.

Execute calls the SetupControls method to configure and layout the elements on the dialog form using the settings provided in the TTaskDialog instance.

AParentWnd contains the handle for the form that is used as the parent for the dialog form. The value is compared to the handles for the forms on the current Screen. When found, the form instance is assigned to the PopupParent property for the dialog form. When not found, the currently active form on the screen is used as the PopupParent.

Execute calls the ShowModal method (in TCustomForm) to manage modal display of the dialog form in the application, and to start the processing loop for the modal form. ShowModal sets the return value for the method.

When ShowModal has been completed, values from the updated form are applied to the TTaskDialog instance which created the dialog. This includes values like:

• The query result and query item index (when used).
• The value from the simple query control (when used).
• The verification check box state (when used).
• The identifier for the selected radio button returned in the ARadioRes argument.

ExecuteLCLTaskDialog is an Integer function used to execute an emulated task dialog form for the specified TCustomTaskDialog instance. It is a convenience routine called from the Execute method in the widgetset class instance for those platforms which do not support the native Task Dialog API.

ExecuteLCLTaskDialog creates a temporary instance of TLCLTaskDialog and calls its Execute method using the arguments to the routine. The return value contains the result from the Execute method in the dialog form; -1 indicates that ADlg did not contain a valid TCustomTaskDialog instance. Otherwise, it contains the modal result from the dialog form.

TLCLTaskDialogIcon is an enumerated type with values which represent the icons available as the main icon on an emulated task dialog form.

TLCLTaskDialogFooterIcon is an enumerated type with values which represent the icons available as the footer icon on an emulated task dialog form.

IconMessage is a String function used to get the title displayed on an emulated task dialog for the specified icon. It is used in the implementation of TLCLTaskDialog to retrieve the title on the emulated task dialog when the value has not already been assigned. The return value contains the translated resource string associated with the index value in the Icon argument. For example:

tiWarning

Returns rsMtWarning.

tiQuestion

Returns rsMtConfirmation.

tiError

Returns rsMtError.

tiInformation, tiShield

Returns rsMtInformation.

Other values

Returns an empty string ('').