You can optionally hide notebook tabs, scrollbars and line number display.

This program was started as one more test and example of the GTK3 bindings for the Nim programming language, but has evolved fast to a nice and useful tool for Nim development. Its primary target is GNU/Linux — it may work also on other operating systems including Windows or macOSX, but that is untested and will currently not be active supported by the original author.

If you have no intention coding in Nim language or absolutely do not like the GTK3 GUI toolkit, then this software is definitely not for you. In the best case you actually consider doing some GTK3 GUI coding yourself, but that is optional. And it should be clear that this tool can not really compare with powerful editors like Vim or Emacs or proprietary editors. Maybe in a later stage it can become comparable to GEdit, the default Gnome/GTK editor. Well not really, OpenHub reports 100k lines of C code for GEdit, while this tool has currently less than 2k lines of Nim code, and it will never have more than a few thousand lines:-)

The largest benefits of this tool is the full nimsuggset integration and easy customization by hacking the source code.

GTK is not very popular currently — mailing lists and IRC have very low activity, which makes it really hard to find community support for coding problems. Some reasons for this may be that GTK is not really cross platform with native look and feel, and that it’s object oriented design coded in plain C is a bit strange. But on the other hand its C API makes language bindings easily available for many programming languages.

The currently used oldgtk3 GTK3 bindings for Nim are not really high level. This means that the GTK3 widgets can not be extended in the same way as Nim objects, and that it can be necessary to free objects or memory manually. Both is not really a big problem, we can use GObject macro system to subclass widgets, we can put widgets into Nim object or create other references between Nim objects and GTK widgets, maybe with hash maps. Or we may use g_object_set_data()/g_object_get_data() to extend widgets derived from GObject base class with custom data. And manual memory deallocation is only necessary in rare cases, because GTK uses reference counting: Widgets are generally put into containers like boxes or windows — when the containers are destroyed the children are unreferenced and destroyed automatically. This works not bad in C, and works in Nim also. The low level structure of the oldgtk3 GTK3 bindings has the advantage, that the Nim code has the same basic structure as C code, so the available C examples can be used as guides. For example this tool is based on GTK_Source_View C examples and Gnome application examples.^[1]

Maybe later someone will port NEd to the high level gintro bindings.

The biggest problem is unfortunately that we need some knowledge of GTK3 and the related libraries when we intent to do serious GUI development. The C API documentation is really not that bad, but it is large and learning it can take some time and effort.

Currently this editor is only tested on 64 bit GNU/Linux with GTK 3.22 (Gentoo AMD64). You need a working Nim compiler (version 0.17.2 or higher) and a working installation of Nim’s nimsuggest tool. And GTK 3.22 or higher and related packages, including GtkSourceView and maybe additional the related developer files.

This repository uses the oldgtk3 nimble package.

Install through Nim’s package Manager Nimble is currently not supported due to name conflicts with old legacy GTK2 packages which are part of Nim’s standard software base.

To install oldgtk3 package and NEd editor open a terminal window and execute these commands:

The make_it build script is necessary because we have to generate resource files from the XML source files for the GUI. That script calls gcc C compiler, you may try to modify it for clang. And you may add option -d:release to get a smaler and faster executable without included debugging code.

Note: This tool uses Gnome’s gsettings for permanently storing user preferences. To reset these states this command can be used:

`gsettings --schemadir "." reset-recursively "org.gtk.ned"''

Maybe you want to try the included color scheme and syntax highlight XML file? In that case you may consult the gedit instructions. On my Linux box I put these file where the other GtkSourceView files reside:

That nim.lang file contains code to generate vertical bars to indicate indentation, which may look ugly with other color schemes. For that case, just remove these lines at the bottom of file nim.lang:

Or you may try the syntax-highlighting file from Aporia Editor.

Unfortunately you can launch it for testing only this way, from inside its directory. When that test is sucessfull, and you intend to really use it, then installing the gsettings configuration is necessary. One method would be this:

Unfortunately that can be done only with administrator rights, and I don’t know how it could be done on Windows or Mac.

The title bar of the Gnome Desktop should display a NEd menu with a Preferences item, which allows you to select fonts and color schemes, and other configuration options. Proportional fonts are supported, but some have tiny spaces unfortunately. You may try the Input font series, which are free of charge for personal use. For medium size (27") 4k displays the overpass fonts look nice, I am using them for the whole Gnome desktop currently. The preferences dialog allows to tune display of line numbers, notebook tabs and scrollbars. And you can change some search options. The Gears menu on the top right of the main window has entries for splitting the current view vertically or horizontally — you can change the size of the split views with an invisible slider. And you can reposition notebook tabs by grabbing the tab with the textual label and moving it onto other tabs (drag and drop). (That does not work when tabs are hidden, and needs some skills: Mouse pointer changes shape when drop position is reached.) Generally new views are opened in the notebook^[2] which contains the last active view — the one which had focus (input cursor ) recently. If the active view has title Unsaved and contains no text, that one is used for the new file. (Remember, it has to be active, so you may have to click into that text area before to indicate that you really want to fill that one.) If you try to open an already opened file again, you will get a new view of that file using the already existing test buffer. Generally you use a different notebook for that so that both views are visible at the same time and you can edit the buffer at different locations.

For vertical scrolling you can use the mouse wheel, the slider at the right side of the text, or keyboards keys. Pressing the right mouse button opens a context menu with cut/copy/past and undo support.

Most functionality is provided by GtkSourceView and related widgets, that includes text input, cursor movement, scrolling, selecting text with the mouse and much more.

You may enter search terms into the search text entry — occurrences are highlighted immediately in the text area. If you enter a number prefixed with ':' view will scroll to that line. If the cursor is in the text area, you may press Ctrl / to activate the search entry — pressing Return key brings you back into text area

Ctrl+G and Ctrl+Shift+G scrolls to next or previous occurrence. Or you can use Ctrl+F in the text area to find the word under the cursor or the selected text. Pressing Ctrl+F again turns of highlight.

Many useful keyboard shortcuts are already defined by GTK itself. These are listed in the table below. I tried not to modify these predefined ones, because you may be already familiar with it. The Nim specific shortcuts are explained in detail below this table.

Shortcuts are not user customizable currently — I am not sure if there would be a real advantage, but of course we may add that later.

The editor itself adds currently these keyboard bindings:

• Ctrl W : Goto definition or What is: Place cursor over a proc name and press Ctrl W — a new tab opens and cursor jumps to that name. If an empty view titled Unnamed is available, that one is used. If you select Reuse Definition View in preferences, than an existing definition view is reused, otherwise new views are opened. If more than one notebook are open, then you can select which of these are used for new definition views: Click into one of the views of the desired notebook, and then use Mark Target from Gears menu. Later we may add variants of this Goto Definition functionality, maybe tooltip display of relevant block only.

• Ctrl E : Check source code for errors and mark these with gutter marks, underlining and tooltip description. Error message is displayed when mouse pointer hovers above underlined symbols. You can press Ctrl+N or Ctrl+Shift+N to jump to next or previous error position

• Ctrl F : Find (highlight) word under cursor or selected text. Press again to toggle. Ctrl+G or Ctrl+Shift+G jumps to next or previous position.

• Ctrl Space : If cursor is located over a period, then nimsuggest tries to suggest methods. Try 1.2. which should offer min, max and other float related proc names. If cursor is not located on the right of a period, then GtkSourceView calls its word provider to suggest word completions. Type pro and you should get procs.

• Ctrl U : Usage of symbols. This is some form of smart search, for example you may use it to highlight all occurrences of a variable in a proc. Words with the same text characters but different meaning are not highlighted. Ctrl+N or Ctrl+P jumps to next or previous occurrence, pressing Ctrl+U again toggles highlight.

• Ctrl R : like Ctrl+U but with optional replace. First press does highlight, next press replaces the symbols with the content of the entry in the top right. This function offered by nimsuggest can do replace operations project wide, but this editor restricts the operation to the current file only. Project wide operations would be not hard to support, but may be a bit dangerous and may break other projects.

• Ctrl C : Context. Type a proc name and the opening round bracket — then this shortcut key can be used to display proc parameters in the status bar at the bottom. If more than one proc with that name exists, then next press shows next.

For each language symbol under the text cursor extended information is permanently displayed in the status bar at the bottom. That statusbar may be used for displaying other informations as well — less important information vanished after a few seconds.

You may name one of your text views log.txt, maybe use that name as additional parameter when you launch the editor from command line, or create a new empty view and use Save As from gears menu to change its name to log.txt. If that one exists, then it is used for logging. Default log level is warn which means that warnings and error messages are logged. The search entry can be used to modify log level — type -- followed by error, warn, log or debug. Press Return to activate that level. --log level may give many message, --debug even more.

You may miss the ability to compile and execute programs from within the editor. Personally I have no demand for that. While it would be not difficult to add that functionality, it is not very interesting and needs some effort, because setting of compiler options and program parameters should be possible in the GUI. I may add that later if there really is a demand for that.

Of course more editing functions may be desired, but I do not intent to add too many arbitrary stuff which most people will not use. This editor should remain a simple, easy tool with a clean GUI and without too many keyboard shortcuts. For very special, rarely used task we can always use tools like vim or sed.

The tool is still in an early stage and is not much tested yet. If you should decide to use it already for serious work, then you should always keep backups of your source files, and you should use additional tools like diff to prove source code integrity often by comparing latest edits with recent verified backup.

While nimsuggest is a great tool, it has a few bugs still, which may even crash the program. Other bugs may lead to crashes also, so save your work often. After a crash it may be not possible to restart nimsuggest immediately, which may gave new crashes. After about one minute it should be possible to restart the tool. The reason for this strange behavior is inter process socket communication — the editor uses sockets to exchange data with nimsugest process, and when a crash occurs, the old persisting communication ports block new one for some time.

The GTK related parts seems to work well in most cases. When using split views and hidden scroll bars I got GTK error messages sometimes — that seems to be a bug in GTK which is not really critical and seems to be fixed in latest GTK 3.22 development version.

Generally it would be possible to get all the highlight information from nimsuggest. I already have a local version of NEd which does that — it works fine, but CPU load is really high because for nearly each keystroke nimsuggests has to update highlight.

As I said earlier, we may consider porting NEd to use the high level gintro bindings later. I guess that will be some work, maybe about 100 hours, because we may have to add some missing functionallity to gintro package still.