LCL Defines: what changed

Revision 2 to 3. Removed lines have a minus sign; added lines have a plus sign.

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1	1		This page documents the defines that can be utilized to recompile the different widgetsets of LCL. It isn´t a comprehensive list, but may become one as more defines are added. It also mentions defines that are automatically set when you select various options, such as widgetset, in Lazarus. See Also [[Platform defines]]
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3	3		## Why use defines?
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5	5		Defines allow to add non-standard functionality to LCL, test experimental features or to add debug output that helps testing the widgetsets.
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7	7		The defines are also useful as 'read only' for you to determine, for example, to include particular code on particular platforms. For example -
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9	9		``` pascal
10	10		{$ifdef WINDOWS}
11	11		// do some WINDOWS specific stuff
12	12		{$else}
13	13		// do whatever but only on non-windows platforms
14	14		{$endif}
15	15		```
16	16
17	17		## Recompiling LCL with a define
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19	19		To recompile LCL with a special define go to the Lazarus menu Tools -\> "Configure Build Lazarus". Add there in the Options field:
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21		-	~~`-d<DEFINE_NAME>`~~
	21	+	```text
	22	+	-d<DEFINE_NAME>
	23	+	```
22	24
23	25		So if you wish to add the PassWin32MessagesToLCL define, you will add
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25		-	~~`-dPassWin32MessagesToLCL`~~
	27	+	```text
	28	+	-dPassWin32MessagesToLCL
	29	+	```
26	30
27	31		to this box.
28	32
29	33		## General LCL defines
30	34
31	35		- DEBUG_SHELLCTRLS - Turns on the use of WriteLn to output debug information for the ShellCtrls unit.
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33	37		#### LCL Version
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35	39		Sometimes its necessary to do things differently depending on the LCL (ie Lazarus) version its going to be compiled with. The LCL_FULLVERSION define can be read like this -
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37	41		``` pascal
38	42		{$if (lcl_fullversion >= 2000600)}
39	43		DoSomething(); // only do this for Lazarus 2.0.6 or later
40	44		{$endif}
41	45		```
42	46
43	47		LCL thinks of its versions in that seven digit number:
44	48
45	49		- 2010000 is 2.1.0 or 2.01.00.00
46	50		- 2000600 is 2.0.6 or 2.00.06.00
47	51
48	52		#### PLATFORM
49	53
50	54		You would not normally set one of these, they are set for you when you choose compile options in Lazarus. Useful to read to make platform specific decisions at compile time.
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52	56		- UNIX - eg, Linux, macOS, Ultrix
53	57		- WINDOWS - all MS Windows platforms
54	58		- DARWIN - macOS
55	59
56	60		There are many more ....
57	61
58	62		#### Widget Set
59	63
60	64		You would not normally set one of these, they are set for you when you choose compile options in Lazarus. Useful to read to make widget set specific decisions at compile time.
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62	66		- LCLCOCOA
63	67		- LCLCARBON
64	68		- LCLGTK2
65	69		- LCLGTK3
66	70		- LCLQt (for Qt4)
67	71		- LCLQt5
68	72		- LCLQt6
69	73
70	74		## Win32 defines
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72	76		- DisableWindowsUnicodeSupport - Turns off Unicode support on Windows. The win32 interface gives string in ansi encoding to the LCL (instead of UTF8).
73	77		- DisableVistaDialogs - Turns off Windows Vista (and higher) file dialogs ([IFileDialog](https://learn.microsoft.com/en-us/windows/win32/api/shobjidl_core/nn-shobjidl_core-ifiledialog)) and uses the older style dialogs.
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75	79		## WinCE defines
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77	81		- VerboseWinCE - Turns on the use of writelns to output debug information. Useful in desktop windows to trace bugs which are reproducible in the desktop too.
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79	83		## Gtk defines
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81	85		- LCLGTK2 - Set when you choose the GTK2 widget set. Treat as read only.
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83	87		- LCLGTK3 - Set when you choose the GTK3 widget set. Treat as read only.
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85	89		- DebugLCLComponents - This activates saving information on every creation or destruction of LCL components, device contexts, gdi objects (pen, brush, font, ...) and main widgets. It will spot mem leaks and double frees with stacktraces.
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87	91		- TraceGDICalls - This activates saving information on every creation or destruction of gdi objects (pen, brush, font, ...). It will spot mem leaks and double frees with stacktraces.
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89	93		- GTK2_USE_OLD_CAPTURE - As of lazarus 0.9.29 r27638 we use new way of capturing (TGtk2WidgetSet.SetCapture). Old way can be reached with this define.
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91	95		It's used only for debugging purposes (eg. diff in capturing before old & new code) if some bug is filled against gtk2 capturing.
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93	97		- USE_GTK_MAIN_OLD_ITERATION - As of lazarus 0.9.29 r27896 we use g_main_context* instead of g_main* which is deprecated from gtk2-2.2.
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95	99		This define fixes sending/receiving messages via PostMessage() from other threads than main.Also, we hook g_main_context's poll function to make g_main_context_wakeup accurate.From glib2 \>= 2.24 g_main_context_wakeup is enough, but for smaller versions we need to check if new message arrived (from another thread), and interrupt main_context_iteration. For those who want to use deprecated gtk_main_* there's USE_GTK_MAIN_OLD_ITERATION.
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97	101		- GTK2OLDENUMFONTFAMILIES - As of lazarus 0.9.31 r35400 TGtk2WidgetSet.EnumFontFamiliesEx() does not use raw X11 fonts naming, but pango via fontconfig.
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99	103		Old fashioned font names can be used with this define.
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101	105		- GTK2USEDUMMYNOTEBOOKPAGE - As of lazarus 1.1 svn revision 39882 dummy notebook page isn't used anymore for gtk2 notebook. If some old gtk2 version
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103	107		needs it just use this define and pls. report issue about gtk2 version and needed dummy notebook page.
104	108
105	109		## Qt defines
106	110
107	111		You can use the following defines while building LCL to configure your Qt Interface:
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109	113		- LCLQT - Set when you choose the Qt4 widget set. Treat as read only.
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111	115		- LCLQT5 - Set when you choose the Qt5 widget set. Treat as read only.
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113	117		- VerboseQt - Writes extensive debug information about the creation and deletion of Qt objects and LCL Objects to the StdOut.
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115	119		- VerboseQtWinAPI - Writes extensive debug information about the Qt implementation of the functions on the LCLIntf unit to StdOut.
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117	121		- VerboseQtEvents - Writes extensive debug information about qt events passed via event filter to the StdOut. If defined VerboseQt then this define isn't needed.
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119	123		- VerboseQtWinAPI_MISSING_IMPLEMENTATION - Writes extensive debug information about the MISSING Qt implementation of the functions on the LCLIntf unit to StdOut.
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121	125		- QTOPIA - Build for qtopia/embedded Qt Interface. See also [[Qt4 binding\|Supported Platforms of FreePascal Qt4 binding]].Do not use QTOPIA define (comment it) if you build qt application for eg. Nokia N9 phone (arm) - it's a pure X11 app, so QTOPIA must be off.
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123	127		- QT_NATIVE_DIALOGS - Build with native dialogs (TOpenDialog, TSaveDialog ...). In that case there's no eg. OnFilterChanged() events since Qt uses static functions for native dialogs.
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125	129		- QTDIALOGS_USES_QT_LOOP - As of Lazarus svn r23536 qtlcl uses LCL loop for QDialog and QFileDialog classes (TQtDialog, TQtMessageBox, TQtFileDialog). If you want to use "old" (original Qt way) then you can use this define, and QDialogs should run in it's own loop managed by Qt. This define doesn't do anything in case we use QT_NATIVE_DIALOGS (for TQtFileDialog only).
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127	131		- QT_ENABLE_LCL_PAINT_TABS - as of r25354 used to allow LCL to paint over tabwidget tabs. PaintEvent from tab provides rect in tab coordinates.
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129	133		- QT_DRAWTEXT_MAP_TO_CLIPRECT - there's an issue (fixed already) [1](http://bugs.freepascal.org/view.php?id=17678) about TCanvas.TextRect() with qtlcl. If you enable QT_DRAWTEXT_MAP_TO_CLIPRECT then Qt will paint your text with respect to DT_WORDBREAK (testpaintrect_2.png), otherwise it works like other widgetsets (testpaintrect_1.png).
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131	135		- VerboseQtCustomControlResizeDeadlock - Writes debug information about intercepted deadlocks inside TQtCustomControl when resized.
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133	137		- DebugQtGDIObjects - writes debug info about TQtGdiObjects class (checks validity of HGDIObj in IsValidGDIObject())
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135	139		- QTSCROLLABLEFORMS - Central widgets of forms are QAbstractScrollArea class, this is enabled by default except if the QTCOCOA define is enabled. If you want less CPU/memory intrusive TCustomForms then uncomment this define. In that case we use QWidget as central widget of TCustomForm, but in that case there's no scrollbars in TCustomForm (eg TCustomForm.AutoScroll means nothing, same applies to TCustomForm. Vertical & Horizontal scrollbars.
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137	141		- QTCOCOA - Automatically enabled if we are on DARWIN and CPU=64 bit.If this define is enabled QTSCROLLABLEFORMS is disabled. When QTSCROLLABLEFORMS is enabled with QTCOCOA there are various crashes which aren't fixed yet.
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139	143		- QtUseNativeEventLoop - On non X11 targets we use the Qt native loop instead of the LCL one. Valid only for Qt5 widgetset.
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141	145		### Legacy
142	146
143	147		Many Qt defines have become unnecessary, entries moved here for clarity.
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145	149		- USE_QT_4_3 - The default Qt version utilized by the interface is 4.2 or superior. By setting this define you allow the interface to use 4.3+ features, like MDI Forms. - Made default and removed as of 0.9.25
146	150		- QT_HIDDEN_BUTTON_WORKAROUND - This activates a work around for a LCL miss-behavior which makes it create a hidden button to overcome some Gtk problem. This should be removed after LCL is fixed. Link for the bug: <http://www.freepascal.org/mantis/view.php?id=9152>
147	151		- QT_LAZARUS_IDE_WORKAROUND - Activates workaround for invisible mainmenu inside lazarus ide, also moving offsets of TGraphicControl descendants , because geometry of form doesn't take TMainMenu height and TToolbar height into account. This should be removed, as soon as we fix offsets, and accounting of TMainMenu & TToolBar height.
148	152		- VerboseQtWinAPI_DEBUG_CLIPBOARD - Writes extensive debug information about LCL clipboard operations.
149	153		- QT_NO_MENU_EFFECTS - Turns off menu effects, fading and animating, which sometimes produces problems (eg. stays visible even they are closed). It is also possible that this is an Qt bug, but have to check it first.
150	154		- USE_QT_44 - The default Qt version utilized by the interface is 4.3 or superior. By setting this define you allow the interface to use qt 4.4 features like better QPrinter,QPainter support etc.Also, if you use this define, you must download qt bindings for 4.4 (1.66 or superior). as of lazarus svn r 21913 qt-4.5.X is default (no more USE_QT_XX defines).
151	155		- USE_QT_45 - The default Qt version utilized by the interface is 4.3 or superior. By setting this define you allow the interface to use qt 4.5 features like better QPrinter,QPainter support etc.Also, if you use this define, you must download qt bindings for 4.5 (1.69 or superior). as of lazarus svn r 21913 qt-4.5.X is default (no more USE_QT_XX defines).
152	156		- QTSizeFix - fixes resizing overhead by reducing InvalidateClientRectCache() calls to minimum.Now only TQtPage calls it from resize event. Works ok with -dOldAutoSize and especially with new autosize algorithms.Will be set as default soon (and removed define). as of lazarus svn revision 25065 this is default behaviour, define removed.
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154	158		## Carbon defines
155	159
156	160		List of Carbon defines used to show debug info when tracing:
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158	162		- DebugEventLoop
159	163		- VerboseObject - Carbon interface application
160	164		- VerboseTimer
161	165		- VerboseWinAPI
162	166		- VerboseLCLIntf
163	167		- VerboseMouse
164	168		- VerboseCursor
165	169		- VerboseKeyboard
166	170		- VerbosePaint
167	171		- VerboseCanvas
168	172		- VerboseMenu
169	173		- VerboseScroll
170	174		- VerboseWidget - TCarbonWidget class
171	175		- VerboseAppEvent - Carbon application event handlers
172	176		- VerboseControlEvent - Carbon control event handlers
173	177		- VerboseWindowEvent - Carbon window event handlers
174	178		- VerboseCommonEvent - Carbon common event handlers
175	179		- VerboseWSClass - TCarbonWS classes
176	180		- VerboseCarbonTrayIcon - TCarbonWSTrayIcon verbose mode
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178	182		Other defines:
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180	184		- CarbonUseCocoa - Activates using Cocoa controls. Removed in Lazarus 0.9.29
181	185		- CarbonDontUseCocoa - Deactivates using Cocoa controls. Added in Lazarus 0.9.29
182	186		- CarbonUsePrivateAPIs - Activates using _NSGetCarbonMenu in TTrayIcon. Not very useful at the moment.
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184	188		## FPC Optimization Defines
185	189
186	190		There are also a number of defines possible that apply to the FP Compiler - see [[Optimization\|Optimization in Code]]
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188	192		## See Also
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190	194		[Free Pascal Compiler Documentation - Compiler defines during compilation](https://www.freepascal.org/docs-html/prog/progap7.html) such as CPU, Platform, compiler ability etc.
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192	196		---
193	197		From the Free Pascal wiki, page "LCL Defines", as it stood on 2024-01-26 after a change by Alextpp, out of the wiki's dump of 2024-05-26. Copyright stays with the author who wrote it, according to the old wiki's [[Licensing]] page. If you have concerns about this material, [message the admin](/wiki-contact).
194	198		Category: LCL

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