Get Involved/development/IDE configuration/Qt Creator

Qt Creator is an IDE from Qt.

A screen recording version is available https://www.youtube.com/watch?v=ASnDeEaXnbI

Features

Qt Creator is a good choice when starting to contribute to KDE.

Qt Creator has: support for kdesrc-build, a good debugger, source code navigation, Qt widgets UI designer, basic QML editor, QML debugger, Qt resources editor, Qt project templates, good CMake support, C++ static analyzers.

Additional features:

Source code navigation: switch header/source, follow symbol, switch between function declaration/definition, find references, open type hierarchy, open include hierarchy.
Refactor rename symbol.
Views: class view, tests view, document outline view and document outline combo box, CMake structure view, file system view.

For best results, download Qt Creator from the Qt website. https://www.youtube.com/watch?v=QVgInye6HDA

kdesrc-build

After you configure kdesrc-build and you can correctly build a KDE project such as kcalc.

Edit ~/.config/kdesrc-buildrc . It should look like:

...                                                                                                    
    include-dependencies true
...                                                                                                               
    kdedir ~/kde/usr
...                                                                                                              
    source-dir ~/kde/src
...                                                                                                                
    build-dir ~/kde/build
...                                                                                
    cmake-options -DCMAKE_BUILD_TYPE=Debug
...

The line above is important in order to use the debugger from Qt Creator.

Make sure you have the correct number on the line num-cores .

Build kcalc, make sure there are no errors:

kdesrc-build kcalc

Qt Creator

Install Qt Creator. E.g. download from the Qt website the latest version. Or e.g. from your current Linux distribution's packages. E.g.

apt install qtcreator

Start Qt Creator. E.g. from a terminal

qtcreator &

From the qtcreator main menu

> File > Close All Projects and Editors

> File > Open File or Project ~/kde/src/kcalc/CMakeLists.txt

Left Sidebar > Switch to Projects mode Ctrl+5 > Manage Kits... Under Manual, remove all kits except "Desktop (default)". E.g. select Manual > "Imported Kit" > press the "Remove" button > press the "Apply" button.

Button "Import Existing Build..." > Directory: ~/kde/build/kcalc > Choose.

Everything should be configured correctly.

Left Sidebar > Switch to Projects mode Ctrl+5 > Active project: kcalc. Build & Run: not the Desktop kit. Build Settings > build configuration: "Debug2".

Click on the left sidebar, the button above "Run Ctrl+R". It should show: Project: kcalc. Kit: not the Desktop kit. Deploy: Deploy Configuration. Build: Debug2. Run: kcalc.

CMake configure was run automatically. You can run it again from the Qt Creator main menu > Build > Run CMake.

You can build by pressing the hammer icon on the lower left with tooltip "Build Project Ctrl+B". Or from the Qt Creator main menu > Build > "Build Project Ctrl+B".

Left Sidebar > Switch to Edit mode (Ctrl+2) > Select "Projects" from the combobox. In the "Projects" left hand treeview > kcalc > kcalc > Source Files > double click on the file kcalc.cpp. The file kcalc.cpp will be shown in the editor view. Click inside the source code in text editor.

In the text editor's top bar > function/identifier/method/type/symbols combobox, select the last item: main(int, char***) -> int. Click on the line with the opening curly bracket of the function main. From the main menu > Debug > Set or Remove Breakpoint (F9).

Left Sidebar > Start debugging of startup project. The debugger will start correctly and break on the source code line with the curly bracket.

From the main menu Debug > Step Over (F10)/Step Into(F11)/Step Out (Shift+F11).

If Qt Creator fails to run the executable correctly

In Qt Creator, if "Run" or "Debug" fails with errors in "Application Output Alt+3" tool window. Errors about not being able to find files or directories.

QML apps are more often affected by this than Qt widget apps.

In the left hand bar > "Switch to Projects mode Ctrl+5" > Build & Run > Imported Kit > Run > Run Settings > Environment > Use Build Environment > press the Details button > press the "Reset" button if possible > press the "Batch Edit..." button. Paste in there, the text below, then press the OK button.

PATH=+/home/username/kde/usr/bin
XDG_DATA_DIRS=+/home/username/kde/usr/share
XDG_CONFIG_DIRS=+/home/username/kde/usr/etc/xdg
QT_PLUGIN_PATH=+/home/username/kde/usr/lib/x86_64-linux-gnu/plugins
QML2_IMPORT_PATH=+/home/username/kde/usr/lib/x86_64-linux-gnu/qml
QT_QUICK_CONTROLS_STYLE_PATH=+/home/username/kde/usr/lib/x86_64-linux-gnu/qml/QtQuick/Controls.2/