Add example for Widget window in Qt Quick #4
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Example app wher a window bounces across the screen, like an old DVD player's logo would. You control the text through one of two identical forms, one implemented in QML and the other in Widgets. The example code follows best practices. Due to limitations with Wayland, it only works on X11 on Linux.
Blog-projects/Widget-window-in-Qt-Quick-app/widgetFormHandler.cpp
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| void closeEvent(QCloseEvent *event); | ||
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| private slots: | ||
| void on_lineEdit_textChanged(const QString &arg1); |
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on_* is definitely not best practice (no error at compile time in case of a mismatch). Please use a real connect to PMF.
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Switched to explicit, modern, connects. Removed confusing on_ prefix.
Are my declarations and casing correct or can these be improved?
Blog-projects/Widget-window-in-Qt-Quick-app/fontcontrolswidgetsform.h
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Blog-projects/Widget-window-in-Qt-Quick-app/widgetFormHandler.cpp
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- Dropped on_ from UI form actions naming pattern - Manually connected to UI form actions - Made getters const - Renamed getters to follow - Turn fontList into a static const member function - Indicate function override
| emit textChanged(); | ||
| } | ||
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| const QString FontControlsWidgetsForm::font() |
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Misunderstanding.
Returning a const QString serves no purpose (on the contrary - it prevents move semantics for the caller)
When I said "make those methods const", I meant marking the actual methods themselves as const:
QString FontControlsWidgetsForm::font() const
(both in .h and .cpp)
(applies to all getters)
The purpose is to indicate (and ensure) that the member variables are not (and cannot be) modified in such methods, because in a const method, all member variables are const.
| return ui->fontComboBox->currentFont().family(); | ||
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| void FontControlsWidgetsForm::closeEvent(QCloseEvent *event) { |
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Inconsistent formatting: you inserted a newline before '{' in most other methods (which is indeed more common).
You could grab the _clang-format from e.g. KDABViewer and run clang-format over the whole code, for consistent formatting.
| QApplication::quit(); | ||
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| void FontControlsWidgetsForm::fontComboBox_currentFontChanged(const QFont &f) |
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OK I see why you asked about casing... This snake/camel mix is weird ;)
Suggestions:
slotFontChanged
onFontChanged
or in you really need to mention the originating widget, say if you have two lineEdits and you were connecting to textChanged() from each, you'd say something like slotNameChanged and slotCountryChanged or possibly slotNameTextChanged/slotCountryTextChanged. But it's not like the exact name of the signal has to be in the slot name. Only if you were connecting to multiple similar signals.
| signals: | ||
| void textChanged(); | ||
| void fontChanged(); | ||
| void pushButton_clicked(); |
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| Q_OBJECT | ||
| QML_ELEMENT | ||
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| public: | ||
| explicit Timer(QObject *parent = nullptr); | ||
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| Q_INVOKABLE int deltaTime(); |
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Q_INVOKABLE int deltaTime() const;
| m_window = new FontControlsWidgetsForm(); | ||
| m_window->setVisible(false); | ||
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| QObject::connect(m_window, &FontControlsWidgetsForm::pushButton_clicked, this, &WidgetFormHandler::toggleWidgetsWindow); |
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Remove "QObject::", unneeded, this is a QObject subclass, it's in scope.
| #ifndef WIDGETFORMHANDLER_H | ||
| #define WIDGETFORMHANDLER_H | ||
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| #include "fontcontrolswidgetsform.h" |
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isn't class FontControlsWidgetsForm; enough in the header?
(and of course, do the real #include in the .cpp file)
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| #include <QObject> | ||
| #include <QQmlEngine> | ||
| #include <QWidget> |
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| Q_INVOKABLE int deltaTime(); | ||
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| signals: |
Example app where a window bounces across the screen, like an old DVD player's logo would. You control the text through one of two identical forms, one implemented in QML and the other in Widgets. The example code follows best practices.