IDE tricks: what changed

Revision 4 to 5. Removed lines have a minus sign; added lines have a plus sign.

Old	New		Line
1	1		## Create a new file with Open file
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3	3		You can create a new file and save it, or you can create a new file with filename and file type in one step: Just open file (`Ctrl+o`) and select a nonexistent filename. For example: unit1.pas. The IDE will ask you if it should be created.
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5	5		## Customize new unit / form
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7	7		Since 0.9.27 you can right click on the 'New unit' (New form) speedbutton and set the file type that should be created. You can register more file types via the IDEIntf or the project templates package.
8	8
9	9		## IDE macros
10	10
11	11		[[IDE Macros in paths and filenames]]
12	12
13	13		## IDE directives
14	14
15	15		[[IDE directives]]
16	16
17	17		## Getting the compiler command line parameters created by the IDE
18	18
19	19		You can copy the parameters from Project -\> Compiler Options -\> Show Options. Here the paths are relative to the project directory. So in most cases you can copy them without adjusting.
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21	21		The parameters are also saved to the *.compiled file. For example if your project is called test1.lpi, then a test1.compiled is created. It is a simple text XML file, so you can just copy the options and adjust the paths to compile on another computer. The file is put into the same directory, where the executable is created.
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23	23		For packages this works the same.
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25	25		This way, you can compile your (hopefully working and bug free) code, outside of the Lazarus IDE.
26	26
27	27		## Closing all editor files except one
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29	29		Under GTK (available for Linux, macOS and FreeBSD) the source editor pages have a close button to the right of their page name. Press the `Ctrl` key while clicking on the button, closes all files except the clicked one.
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31	31		## Component palette
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33	33		### Finding a component in the palette
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35	35		You know the component name, or part of it, but you don't know on which page it was? This tool finds it: Right click on any component in the palette to open the popup menu. Select 'View all' from the menu; this will pop open a dialog(also you can achieve it by pressing `Ctrl+Alt+P`). Enter the (partial) component name in the 'Find' box to filter the list.
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37	37		### Open the package of a component in the palette
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39	39		Right click on the component to open the popup menu, then choose open package.
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41	41		### Find the source declaration of a component in the palette
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43	43		Right click on the component to open the popup menu, then choose open unit.
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45	45		### My application freezes my Linux desktop while debugging
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47	47		X (your desktop) can freeze, when an application that grabbed the mouse is stopped by gdb (the debugger).
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49	49		### Using a second X session
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51	51		You can start a second X by:
52	52
53		-	~~` X :1 &`~~
	53	+	```text
	54	+	X :1 &
	55	+	```
54	56
55	57		with `Ctrl-Alt-F7` you switch to :0 and with `Ctrl-Alt-F8` you switch to :1 after that you can start a second gnome session by:
56	58
57		-	~~` gnome-session --display=:1 &`~~
	59	+	```text
	60	+	gnome-session --display=:1 &
	61	+	```
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59	63		### Using VNC
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61	65		You can use vncserver/client by installing tightvncserver or realvncserver. Start the server with:
62	66
63		-	~~` vncserver :1`~~
	67	+	```text
	68	+	vncserver :1
	69	+	```
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65	71		AFAIK, a session is also started. You can connect to the vncserver with vncviewer.
66	72
67	73		### Debug the application on the second server
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69	75		In Lazarus, in the run parameters for your project, check "use display" and enter
70	76
71		-	~~` :1`~~
	77	+	```text
	78	+	:1
	79	+	```
72	80
73	81		Now your application will run on the second server, so when it is being debugged, only the second server will freeze (but that won't affect you since you are debugging on the first).
74	82
75	83		## Compiling the IDE fast
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77	85		Working on Lazarus itself means rebuilding the IDE many times. If you use the following tricks and have enough memory and a recent CPU, you should be able to recompile the IDE in a few seconds.
78	86
79	87		- Put the Lazarus sources on a fast hard disk or solid state drive. Not on a slow network filesystem.
80	88		- Install only needed packages.
81	89		- Set USESVN2REVISIONINC=0 to skip the update of the revision.inc file.
82	90
83	91		## DebugLn of the IDE or a LCL application
84	92
85	93		The IDE writes many useful hints via [[DebugLn]]. You can get these this way:
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87	95		- Windows: start Lazarus with the command line parameter --debug-log=filename.txt.
88	96		- Linux/FreeBSD/macOS/Solaris: just start Lazarus in a terminal.
89	97
90	98		This is a general LCL feature.
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92	100		## Finding the source file of an IDE window
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94	102		- Open the IDE window.
95	103		- Press `Ctrl+Shift+F1` to open the help editor.
96	104		- Remember the window classname. Close the window.
97	105		- Use [[IDE Window: Find in files\|Find In Files]] to find the source file of the class.
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99	107		## Opening a Terminal Windows from the IDE
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101	109		Its often handy to be able to open a terminal in your current project's working directory. Maybe to use a revision control system like git or svn or for a host of other possible reasons. Here is how to add a menu item to Lazarus's Tool's menu. Thanks to taazz and other contributors to the [forum thread](https://forum.lazarus.freepascal.org/index.php/topic,42151.msg294206.html#msg294206).
102	110
103	111		- Click Tools, Configure External Tools
104	112		- Click 'Add' to add a new menu item (under Tools).
105	113		- Set Title to (eg) "Open a Terminal"
106	114		- Set Program File Name to the command on your system that opens a terminal, some suggestions below.
107	115		- Set Parameters to what ever your terminal expects on the command line to open a specific directory and the Lazarus var that points there, \$projPath().
108	116
109	117		Those last two vary quite a lot between systems, if you don't know the first, try looking at a list of running programs, the word 'terminal' is likely to feature. For the second, once you know the terminal's name, look up its man page or google.
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111	119		Some examples include -
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113	121		\| O.S. \| Program File Name \| Parameters \|
114	122		\|----\|----\|----\|
115	123		\| Ubuntu Mate \| mate-terminal\\|\\|--tab --working-directory=\$projPath() \| \|
116	124		\| xfce \| exo-open\\|\\|--launch TerminalEmulator --working-directory \$ProjPath() \| \|
117	125		\| KDE \| konsole\\|\\|--working-dir \$projPath() \| \|
118	126		\| GNOME \| gnome-terminal\\|\\|--working-directory \$projPath() \| \|
119	127		\| Mac (see below) \| /User/\$HOME/bin/ttab \| cd \$projPath() \|
120	128		\| Windows \| cmd.exe \| /k cd "\$ProjPath()" \|
121	129
122	130		![IDE Ext Tool](/wiki-images/3/30/ExtTool.PNG) On the Mac, where everything is so much easier, all you have to do is:
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124	132		1. Install <https://www.npmjs.com/package/ttab>, its only 665 lines, use the path you installed it to instead of the example shown in the table above.
125	133		2. Run it so you can tick its security to access the Accessibility feature.
126	134		3. Then set the Lazarus Tools settings as described.
127	135		4. Then, from within Lazarus, Tools-\>Open Terminal, then similar to 3) tick to allow Lazarus to access the Accessibility thingo.
128	136
129	137		On Windows, its also necessary to tick the "Show Console" as shown in the image on the right:
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131	139		## Object Inspector: Events: Frames: Jump to the source of an inherited event
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133	141		The [[IDE Window: Object Inspector\|Object Inspector]] shows the events of inherited events as ClassName.MethodName. Double clicking will create a new event. `Ctrl+Mouse click` on the combobox will jump directly to the inherited method body, without creating a new method.
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135	143		## Events (Method properties) in the Object Inspector
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137	145		Events (Method properties) are special properties, because they need as value a code address pointer, which does not exist at design time. That's why Lazarus uses the same trick as the Delphi IDE: Every method value can be type cast to TMethod, which contains Data (the object or class pointer) and the Code (the address pointer). At runtime both are set. But at design time the IDE sets Data to a special key value for its internal lookup table and sets Code to nil. This means:
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139	147		- At runtime when the program loads the .lfm file the real method (Data+Code) is used
140	148		- At design time a method value can either be a real method (Data\<\>nil and Code\<\>nil) or a fake method (Data\<\>nil,Code=nil)
141	149		- The compiler has for Delphi compatibility some specials about comparing method values.
142	150		- The = and the \<\> operator only checks the Code, not the Data.
143	151
144	152		Do not use:
145	153
146	154		``` pascal
147	155		if OnMyEvent = NewValue then exit; // wrong, because it compares only Code
148	156		```
149	157
150	158		Because this only compares the Code. Use instead
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152	160		``` pascal
153	161		if CompareMem(@FOnMyEvent, @NewValue, SizeOf(TMethod)) then exit; // correct, checking both Data and Code
154	162		```
155	163
156	164		Here is an example where the = operator fails:
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158	166		``` pascal
159	167		type
160	168		TMyClass = class
161	169		private
162	170		FOnClick: TNotifyEvent;
163	171		procedure SetOnClick(Value: TNotifyEvent);
164	172		public
165	173		procedure Click(Sender: TObject);
166	174		property OnClick: TNotifyEvent read FOnClick write SetOnClick;
167	175		end;
168	176
169	177		procedure TMyClass.SetOnClick(Value: TNotifyEvent);
170	178		begin
171	179		if Value = FOnClick then exit; // bug, checks only for Code, not for data
172	180		FOnClick := Value;
173	181		end;
174	182
175	183		var
176	184		a, b: TMyClass;
177	185		begin
178	186		a := TMyClass.Create;
179	187		b := TMyClass.Create;
180	188		a.OnClick := @a.Click;
181	189		a.OnClick := @b.Click; // same code, but different data, a.OnClick still points to @a.Click;
182	190		end.
183	191		```
184	192
185	193		---
186	194		From the Free Pascal wiki, page "IDE tricks", as it stood on 2021-10-11 after a change by Kai Burghardt, 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).

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