How to select TextEdit after Enabled in Qt? - qt

I want to design a layout with a PushButton and TextEdit. The TextEdit is disabled at first and only enabled when the PushButton is clicked. When the TextEdit is enabled, it should also be selected.
In other words, what I mean is I can start typing straightway in the TextEdit without click to select it after it is enabled. Like when you open a new tab in your browser, the text cursor will automatically go to the address bar without any clicking.
Thanks.

You can use the QWidget::setFocus() function, docs here.

Related

QML Virtual keyboard Hide button not working. Again

There's a similar question here but it seems rather out-dated since I use Qt 5.14. I have a similar problem.
I set the visible property of my InputPanel to active and tried putting the TextField into a TextInput but still I cannot hide the keyboard via the close button available in the bottom right corner .
Currently there are two workarounds for me :
1 ) Adding the onAccepted signal for any TextField or TextInput to hide the Virtual keyboard after hitting Enter (on Real or virtual keyboard , both works)
2 ) Adding a redundant Button to just hide the keyboard
But the clean method for closing it is what a typical user would expect : The specified button in the keyboard
Any help would be appreciated.

qml how to keep focus on TextField

I want to keep focus on TextField. For example i am typing something then tap to button. The focus on TextField is moving to button, that's why keyboard is automatically hiding on Android. I am using Qt 5.9.2. Thanks in advance!
In Qt Quick Controls 2, each control has a focusPolicy property which determines how the control gets focus. The default for controls like Button is Qt.StrongFocus, which means that buttons get focus after being clicked or tabbed into. If you're seeing that a control has focus and you don't want it to, just set its focusPolicy to Qt.NoFocus:
focusPolicy: Qt.NoFocus

How to capture Tab Key in Qt widget

I want to implement my own sequence for changing the focus of the active child widget using the Tab key. How to capture the Tab Key press event? I am using Qt5.2
If you want to change focus with Tab , you don't need to do those works, Qt has it as a feature.
First: set the desired widgets to be Qt::TabFocus or Qt::StrongFocus by QWidget::setFocusPolicy( Qt::FocusPolicy policy )
For example, if you want to rotate between 3 QLineEdit and 1 QCombobox, you have to assure that their focus policy have been set right. (Normally either Qt::TabFocus or Qt::StrongFocus will be set as default, but sometimes you might want to escape some widgets from being tabbed)
Second: go to designer mode and click "Edit Tab Order" to enter the tab-order editing mode
Third: After seeing the numbers, click on them until you got the desired sequence order.
(Picture from Qt official site)
Have a mouse press event or a event filter, get to the point where you have a QKeyEvent
Then only do something if tab was pressed
key_event->button() == Qt::Key_Tab

Qt Popup as a completer window

I need to make some kind of popup window that contains propositions to complete sentences in text editor (QTextPlainEdit). This window needs to be on top of all windows of this application. Also this popup mustn't interrupt typing in the text editor when it appears. I tried different types of flags for QWidget that implements this completer but all I have got is that this completer window is placed above all windows of OS (even if this application is not active) or it interrupts typing in the text editor and makes main window not active any time it appears.
What flags should I use for completer widget?
You could try to use QWidget::setWindowFlags(Qt::Window | Qt::FramelessWindowHint).
Otherwise you could use a customized version of Qt::Popup, by overriding the automatic closing behavior.
You could also try this: if you set the QTextPlainEdit's parent as the completer's parent it should do what you want, provided that the parent does not have a layout (otherwise it will not "float").
The Qt docs contain an example that implements a google-based auto-completer widget, here: http://qt-project.org/doc/qt-4.8/network-googlesuggest.html.
As far as I can tell, they do two things that might be relevant to your situation. One is the flags they set on the popup widget:
popup = new QTreeWidget;
popup->setWindowFlags(Qt::Popup);
popup->setFocusPolicy(Qt::NoFocus);
popup->setFocusProxy(parent);
The other is a custom event filter on the popup widget, which forwards most keypress-events to the editor widget, and closes the auto-completer on Enter or Escape.

Keyboard control of GUI dialogs - Should default button change with focus?

In GUI dialogs, most applications provide for keyboard control as follows:
Enter key - presses the default button. (Default is usually indicated with a bold button border.)
Esc key - presses the Cancel or close button.
Space key - presses widget that currently has keyboard focus.
Tab key - advances focus to next widget.
Question is, when keyboard focus is on a widget that is a button, should the default button be changed to be the one with focus?
I see some issues with this behavior:
The display noise of redrawing buttons to unbold the outline of original default button and rebold the button under focus as being new default.
The Space key is now somewhat redundant with Enter key.
There is no keyboard accelerator to get the normal default button now (Usually the OK button).
However, it seems the trend has been in this direction to change the default button with focus change to another button. What is the rationale for this departure from the early GUIs? It would seem to provide less functionality given there is no way to press the original default button. Did people find that the original model was too complicated for users to understand? I would think keyboard control of dialogs would be a task for advanced users who would have no trouble understanding the model and prefer to have accelerator for current button (Space) and original default button (Enter) at all times.
Note that Qt for one is supporting the change: QPushButton's autoDefault property is responsible for the behavior of changing the default button. By default its value is true. Therefore, you must take extra action to set it to false for all buttons, to prevent them from becoming the default button when focused.
This is not a "departure from the early GUIs", at least not if by "early GUIs", you mean Windows 1.0. The behavior that you describe has been this way since the beginning.
The focused button is always "pushed" when the Enter key is pressed. The default button is only triggered in the following two situations:
The default button has the focus (which it does by default), or
The focus is on a control that does not process Enter key presses (such as a static control, or a single-line textbox that does not have the ES_WANTRETURN style flag set).
The famous Win32 blogger Raymond Chen has a post explaining this behavior (focus specifically on the last two quoted paragraphs):
A dialog box maintains the concept of a "default button" (which is always a pushbutton). The default button is typically drawn with a distinctive look (a heavy outline or a different color) and indicates what action the dialog box will take when you hit Enter. Note that this is not the same as the control that has the focus.
For example, open the Run dialog from the Start menu. Observe that the OK button is the default button; it has a different look from the other buttons. But focus is on the edit control. Your typing goes to the edit control, until you hit Enter; the Enter activates the default button, which is OK.
As you tab through the dialog, observe what happens to the default button. When the dialog box moves focus to a pushbutton, that pushbutton becomes the new default button. But when the dialog box moves focus to something that isn't a pushbutton at all, the OK button resumes its position as the default button.
The dialog manager remebers which control was the default button when the dialog was initially created, and when it moves focus to something that isn't a button, it restores that original button as the default button.
The behavior that I would expect is:
If I press enter when the window just pop up, it should press the default button
If I press tab, I start navigating through the widgets. In this case there are two options:
2.1 I press enter - this event should be delivered to the focused widget. There's no need to change the default button - simply hand the event to the focused widget.
2.2 I press escape. In this case, everything should go back to the state after the window is created.
Notes:
I come from a mixed background - I don't know if I learned this in windows, linux or Mobile OSes! This is just how I expect things to work out.
I don't use the space key (didn't know it's functionality)

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