How to dynamically hide/show widgets in a custom QWidget-based toolbar on window resize?
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Hi everyone,
I'm building a custom toolbar using a plain QWidget instead of QToolBar, and I need to handle widget visibility based on the window size dynamically.
What I want to achieve:
- When the window is wide enough, all child widgets (buttons, labels, etc.) in the custom toolbar are visible.
- When the window becomes narrow, certain widgets should automatically hide, like a responsive or adaptive toolbar.
- This is similar to how toolbars work in modern apps — they adapt their content visibility depending on the available width.
Current setup:
- My custom toolbar is a QWidget added to a layout in QMainWindow.
- I'm adding buttons and other widgets manually to it using a horizontal layout (QHBoxLayout).
- I tried listening to the parent’s resize event, but managing space and knowing when to hide/show specific widgets is tricky.
Questions:
- What's the recommended way to measure the available width inside the toolbar and compare it with the total width of child widgets?
- Should I override resizeEvent() in the custom toolbar and manually calculate visibility per widget?
- Are there any best practices or existing layouts (or custom ones) that help implement this kind of adaptive behavior?
Any tips, examples, or direction would be really appreciated!
Thanks in advance!
-
Hi everyone,
I'm building a custom toolbar using a plain QWidget instead of QToolBar, and I need to handle widget visibility based on the window size dynamically.
What I want to achieve:
- When the window is wide enough, all child widgets (buttons, labels, etc.) in the custom toolbar are visible.
- When the window becomes narrow, certain widgets should automatically hide, like a responsive or adaptive toolbar.
- This is similar to how toolbars work in modern apps — they adapt their content visibility depending on the available width.
Current setup:
- My custom toolbar is a QWidget added to a layout in QMainWindow.
- I'm adding buttons and other widgets manually to it using a horizontal layout (QHBoxLayout).
- I tried listening to the parent’s resize event, but managing space and knowing when to hide/show specific widgets is tricky.
Questions:
- What's the recommended way to measure the available width inside the toolbar and compare it with the total width of child widgets?
- Should I override resizeEvent() in the custom toolbar and manually calculate visibility per widget?
- Are there any best practices or existing layouts (or custom ones) that help implement this kind of adaptive behavior?
Any tips, examples, or direction would be really appreciated!
Thanks in advance!
Hi and welcome to the forum,
@harsh_ag said in How to dynamically hide/show widgets in a custom QWidget-based toolbar on window resize?:
What's the recommended way to measure the available width inside the toolbar and compare it with the total width of child widgets?
There is no other way than to do it manually. If you want some custom behavior you need to calculate and sum the width of your involved widgets and compare it with the available geometry / size of your widget.
Should I override resizeEvent() in the custom toolbar and manually calculate visibility per widget?
Probably. Unless you find something existing that already implements your custom behavior.
Are there any best practices or existing layouts (or custom ones) that help implement this kind of adaptive behavior?
Maybe look at how
QWidgetActionworks in aQToolBar.
(If a regular toolbar is to small to display all toolbuttons/widgets, it adds this extra popup menu via "extension button".
There was this topic where I (and OP) tried to figure out how this works exactly, but unfortunately we couldn't manage to achieve what OP was trying to do.Also maybe
FlowLayoutis something worth to look at.
(custom implementation of a layout, see: FlowLayout Example)
Instead of the new line "jumps", you could add your own implementation of what should happen when your toolbar is getting smaller than the space your items/widgets actually need. -
You should implement a method to show or hide the toolbar based on the window size. From MainWindow::resizeEvent(), you can either calculate when to show or hide the toolbar yourself, or simply pass event->size() to your custom toolbar and let it decide whether it should be visible or not.
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You should implement a method to show or hide the toolbar based on the window size. From MainWindow::resizeEvent(), you can either calculate when to show or hide the toolbar yourself, or simply pass event->size() to your custom toolbar and let it decide whether it should be visible or not.
@Kevin-Hoang said in How to dynamically hide/show widgets in a custom QWidget-based toolbar on window resize?:
calculate when to show or hide the toolbar yourself
OP asked how caculate the visibility of toolbar items, not the toolbar itself. The toolbar should always be visible, if I understood correctly.
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@Kevin-Hoang said in How to dynamically hide/show widgets in a custom QWidget-based toolbar on window resize?:
calculate when to show or hide the toolbar yourself
OP asked how caculate the visibility of toolbar items, not the toolbar itself. The toolbar should always be visible, if I understood correctly.
@Pl45m4 said in How to dynamically hide/show widgets in a custom QWidget-based toolbar on window resize?:
OP asked how caculate the visibility of toolbar items, not the toolbar itself. The toolbar should always be visible, if I understood correctly.
I misunderstood earlier — I thought he was showing or hiding the whole toolbar.
If the toolbar is a toplevel widget or its parent is the MainWindow, then yes, it still makes sense to handle it the way I mentioned. From MainWindow::resizeEvent(), he should pass the size information to the toolbar so it can decide which items to show or hide based on the available space.
