Lazarus 4.0 release notes

Lazarus 4.0 is not yet released. This page is under construction!

LCL Changes

TTaskDialog

Support for Queries

• Because the unit LCLTaskDialog has been deprecated, the query capabilities of LCLTaskDialog.TTaskDialog have been added to Dialogs.TTaskDialog, albeit with a slightly different implementation.
  • New flag tfQuery: adds a query (in the form of a combobox) to the dialog.
    • New property QueryChoices (TStrings): sets the predefined answers.
    • New property QueryItemIndex: sets the ItemIndex of the combobox and holds said ItemIndex when the dialog is closed.
    • New flag tfQueryFixedChoices: control whether or not the user can add his/hers own text to the combobox.
    • New property QueryResult: holds the text of the choice made when the dialog closes.
  • New flag tfSimpleQuery: adds a single line Edit to the dialog. Note: this flag is mutually exclusive with the tfQuery flag.
    • New property SimpleQuery: sets the initial text of the Edit.
    • New property SimpleQueryPassWordChar: sets PassWordChar of the single line query editor.
    • Property QueryResult holds the text of the Edit when the dialog closes.

New events

The following (most of them Delphi compatible) events were implemented:

• OnDialogConstructed
• OnDialogCreated
• OnDialogDestroyed
• OnVerificationClicked. This also updates the Flags property to reflect the current state of the verification checkbox.
• OnExpanded. The associated new property Expanded only has meaning in the context of this event.
• OnTimer
• OnRadioButtonClicked
• OnHyperlinkClicked (Windows Vista+ native dialog only). The associated new property URL only has meaning in the context of this event.
• OnNavigated (Windows Vista+ native dialog only). This event only fires if the dialog has pages (see: MS docs). Pages are not implemented in TTaskDialog, but they might be implemented in a derived class. The event handler must however be in the base class for Delphi compatibility.
• OnHelp. Does not exist in Delphi (even though Delphi does have a protected method DoOnHelp). Triggers when user presses F1 when the dialog is open.

New properties

• CollapseButtonCaption: controls the caption of the Expand/Collapse button when the dialog is in expanded state.
• CustomMainIcon and CustomFooterIcon: icons to be displayed in the dialog (instead of the standard icons) when the flags tfUseHIconMain and tfUseHIconFooter are used.

IDE Changes

Compiler Options

• Added project compiler option for SubTarget.
• Added compiler option Write config instead of command line parameters (@). See here. Useful for passing large amount of paths to the compiler or an easier way to use the Lazarus options in your build scripts.
• Added predefined variable Laz_FullVersion to conditionals. See here. Useful to define Lazarus version dependent command line parameters.
• Wildcards * and ** in search paths. See here.

Debugger

• Alt + Left-Mouse Gutter click / Ctrl-Alt-F5: Add breakpoint (if not yet set) and ,pen properties of breakpoint.

Changes affecting compatibility

LCL incompatibility

TTaskDialog

• The implementation of TTaskDialog has been refactored.
  • Widgetset specific implementation has been moved to the widgetset.
  • The emulated taskdialog has been moved to a new unit: TaskDlgEmulation.
  • The unit LCLTaskDialog has been deprecated.
  • Remedy: if you use TTaskDialog from (now deprecated) unit LCLTaskDialog, use TTaskDialog from Dialogs unit instead.
• Execute() now passes the handle of the active form instead of 0.
  • Reason: it makes Execute() honour the tfRelativeToWindow flag.
  • Remedy: if your code relied on passing 0 as the ParentWind parameter use Execute(0) instead.
• The occurrence of '\n' in e.g. captions is no longer converted to a LineFeed.
  • Reasons:
    • Wrong results if the capion of a (radio)button is set to e.g. 'Save in "c:\new_folder\new.work"'
    • You can have a LineFeed (#10) inside a Pascal string.
  • See also Issue #38676.
  • Remedy: use LineFeed character in captions where applicable.