How to handle a QDialog displayed out of screen? - qt

I have a main widow. I move it to an bottom edge or corner. Then I open a dialog by click some button in it. The dialog is positioned at the center of the main window since I set the main window as its parent. However, the dialog is not displayed on the screen because the main window is at the edge or corner. How to make it displayed on screen?

You can move it with negative coordinates until it becomes on screen:
dialog.move(-dialog.width(), -dialog.height())
This should move it so it's bottom right edge aligns with main windows's top left edge.
Or you could make the dialog parentless and move it in relation to screen coordinates instead:
dialog.setParent(None)
dialog.move(400, 300)

Related

Resize electron.js app from draggable css area

My app uses a frameless window and I made a custom title bar along with it, I set the entire titlebar area to be draggable with -webkit-app-region: drag; so you can position the window on the desktop, but now I can't resize the app from those corners, is there any way to keep both?
Edit: I added -webkit-app-region: drag; to the buttons and the left title area because I lost control of the buttons and I can resize from corners and those edges, but the top edge is still inactive

Android : negative margins behave differently on different versions

I am writing an application where I need to move a view from top to bottom but only when user moves it downward. To move this view I have a button below the view to drag. So initially I place the view beyond top of the view i.e. with negative margin equals the height and only the drag button is visible at the top to user. I see that this works perfectly on Lollipop and view is just at the position where bottom of view matches the top of screen. When I try it on Kitkat and lower versions, the view goes more towards top than the edge of screen. I have this everything in a RelativeLayout.
To show that view is dragged downward I am manipulating bottomMargin and topMargin properties on view.
Has anyone came across similar problems? Thanks in advance.

How to increase the clickable area of a QPushButton in Qt?

The Back button in the top left corner of my touch user interface is a little hard to press on a resistive touchscreen, because the touch events are not so precise at the borders of the screen.
The visual size of the button can't really be increased because the screen space is needed for other things. Thus I would like to increase only the clickable area of the button. So when the user touches somewhere in the top left corner of the screen (as marked in red), the back button should be pressed. Note that the red area also overlaps another button. Ideally, the visual button state would also change to the "pressed" state.
Can anyone give me some pointers in the right direction? I have considered the following things, but I'm unsure which would work.
Overlaying the actual button with a larger, invisible button, painted with a transparent brush. But I have no idea how I could paint the smaller button as "pressed" when the user is pressing the invisible button.
Creating a new class based on QWidget, which has the size of the red area (with invisible background) and contains the actual button. Then relay touch events to the button so that it is pressed when the user touches the empty area.
Subclassing QPushButton and reimplementing QAbstractButton::hitButton to accept points outside of the button's area. But I guess that function would probably isn't even called when I touch outside the widget area.
To occupy more vertical space inside a layout, set buttons vertical policy to expanding.
To increase the clickable area without increasing the visual size, increase the margin.
To have the back button overlapping other buttons, don't put it to a layout. Instead set its parent directly and move it to the corner.
backButton = new QPushButton("< Back", mainWindow);
backButton->setStyleSheet("margin: 30;");
backButton->show();
backButton->resize(150, 90);
backButton->move(-30, -30);

QScollArea doesn't autoscroll when dragging inside it

I have some widgets inside a QScrollArea and I'm dragging between these widgets, the problem is that the QScrollArea doesn't scroll when I'm dragging inside it, so if I want to drag between a widget A to the widget B and the widget B is not visible on the viewport, the QScrollArea doesn't automatically scroll when the mouse moves to the edge of the viewport.
Subclass your scroll area, and add in one of the functions below.
http://qt-project.org/doc/qt-4.8/qwidget.html#mousePressEvent
http://qt-project.org/doc/qt-4.8/qwidget.html#dragMoveEvent
http://qt-project.org/doc/qt-4.8/qwidget.html#dragLeaveEvent // Probably just need this one
When the dragMoveEvent reaches the edge of your widget, or when the dragLeaveEvent happens, detect which edge it is, or left at, and then scroll your area in that direction.
Hope that helps.

How to scale an widget in specified in qt

I have divided my main screen in 4 areas as border-layout as center,right,left and bottom. The right, left and bottom areas are small and contain only buttons. My center area has to display the different widgets and forms depending on the buttons pressed in right/left/bottom areas.
Can anybody suggest how I can design my forms or widgets so that when I show the widget in the center area, it will fit into the center area and all the items inside this will be scaled rationally.
Please refer to the attached image file for a better idea.
If my explanation is not clear please let me know I will try better.
Looks like you already have a decent start. If you only have icons, typically icons won't be able to expand much so you will want your left,bottom and right containers to be non-expanding.
The center container (most likely a QStackedWidget in your case) will be expanding both horizontally and vertically.
You will also need to add spacers at the bottom of left area and right area.
The bottom area can also use spacers on both sides.
In short
Bottom area: sizePolicy: Preferred/Minimum, maximumSize: inf/40
Left area: sizePolicy: Minimum/Preferred, maximumSize: 40/inf
Right area: sizePolicy: Minimum/Preferred, maximumSize: 40/inf
Center area: sizePolicy: Preferred/Preferred, maximumSize: inf/inf
Here is what you can do with drag and drop within QtDesigner
Here is what it looks like
Here is what it will look like expanded. Notice that although the main area is bigger, the buttons sides remain the same.

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