I want to resize everything when i show it in full screen automatically keeping aspect ratio. How can i do it. i use PyQt4 but if you know of C++ then also please tell me.
Hope the code will be not more than 2-3 lines.
Thanks
I suppose you've implemented static layouts with fixed widget sizes and positions in your dialogs/windows. In order to resize the widgets with the window, what you need to do is using dynamic layouts. You best use Qt Designer for the dialog design, else setting up any non-trivial layout can get rather toilsome.
Related
I am using Ubuntu OS.
I am new to GTKMM GUI building application.
I am following the tutorials which they have on their websites.
https://developer.gnome.org/gtkmm-tutorial/stable/sec-helloworld.html.en
I can resize the window with helloworld.set_default_size(500,500);
but I cannot move the position of button("hello world").
It is always aligned at center.
I tried with m_button.set_alignment(0.0,0.0) but nothing seems to be working.
Why it is that much difficult to move button to any position.?
kindly suggest some solution if available.
If you want to place a widget like a button, you have to use some container widget like Gtk::Boxor Gtk::Grid. Inside such container widgets you can place you child widget as you like, but typically not directly per point position.
The container widgets use some internal logic to order and resize the contained widgets.
From the documentation:
Many GUI toolkits require you to precisely place widgets in a window, using absolute positioning, often using a visual editor. This leads to several problems: ...
gtkmm uses the packing system to solve these problems.
You can find the full documentation here:
Multi-item widgets
I did not know if there is a container widget which allows direct positioning by giving a point position. If someone has an additional hint, let us know!
Sometimes automatic is better than manual handling, but sometimes it is not :-)
Quite new to wxWidgets and ran into an issue with sizers, in my program I got quite a few buttons in a custom panel which I would like to add a horizontal scrollbar too. However the different sizers that I've tried all got auto layout which re-arranges my buttons upon start and change the distance between them while resizing, I would like to disable all of this behaviour but can't find any documentation on how to do so. Is it not possible or have I just been going about this the wrong way?
If you use sizers, you should let them manage the layout, of course.
You can use absolute positions if you really want to, but this is strongly not recommended and will not allow you to create the layouts that work in all configurations. But if you do decide to do this (again, you really shouldn't), then you wouldn't be using sizers at all.
I'm wondering if there is a way to make Qt widgets within a QMainWindow widget stretch and scale as the size of the main window is stretched and shrunk. Basically, I'd like the entire window and it's contents to have the same appearance except for size:
At the only way I can think to accomplish this is to get the size of the main window, do the math for every single widget, and reset their sizes any time the main window size is changed, but I'm thinking there's an easier way.
I like this video tutorial on youtube. I'll help you create a layout using QLayout classes. If you use QtCreator/Designer, you can also take a look at the auto-generated ui_MainWindow.XXX file that will clue you in on how it uses some of the UI classes.
As always, QtCreator/Designer has a bunch of hints and tips so you should be able to dig up from the documentation that's embedded in the application.
I've been playing around with QtDesigner for some time now, but I can't find a real solution for my desired layout.
Here's what I'm aiming for, kind of an Eclipse RCP-like layout:
Five drag&dropable widgets which can be rearranged and whatnot (so Dockwidgets). Thats what happend in above screenshot, I just pulled five Dockwidgets into the Mainwindow and populated them with Items. But the problem is that Dockwidgets only snap to the edges of the Mainwindow, and leave space to CentralWidget, which you see in the middle. Is there some way to add a containing widget to the center and fill it with DockWidgets?
On a side note: Is it feasable to do something like this in the Designer? I see why this program is useful, as GUIs can be set up and changed extremly fast, but I feel like stripped of any power on the exact look. I'm kinda itching to (attempt to) write the GUI by hand, because I'm feeling so powerless! :-)
P.S.:How can the screenshot be scaled? It seems overly huge
Unfortunately no. As it says in the documentation
Dock windows are secondary windows placed in the dock widget area around the central widget in a QMainWindow.
I'm having all sorts of size problems with Qt. I am creating my own widgets and using different layouts (generally, I need my own to make them work properly without spending hours on the "powerful" default layouts... which don't lay things out as intended.)
Once I'm done with a widget and its layout though, it doesn't work right. The size is never getting set properly unless I call widget->resize(1, 1); which finally forces a "resize" and makes the widget look correct (i.e. recompute the geometry.) Even the updateGeometry() call has no effect.
This is a dreadful problem when the resize() needs to be called on the parent widget (yuck!) and from what I'm reading should not be necessary were the layouts properly programmed.
Is there a sample that works and is not several thousand of lines long, or does Qt require several thousand lines to make anything work perfectly, even the simplest widget?
What are the minimal functions to be called to make a widget & its layout work at once?
Thank you.
Alexis
P.S. I tried to implement the sizeHint(), minimumSize(), maximumSize(), others that I'm missing? I was hoping that would be enough. Obviously, I also implement the setGeometry() on the layout to resize the children appropriately.
--- addition 1
There is a sample image with a layout that clearly isn't available as is in Qt. The positioning, functions, and colors of the different keys is XML driven and works for any keyboard in the world.
(note, this sample doesn't show the Enter key displayed on two rows and wider below than at the top; more or less, not doable at all with the regular layouts; of course, it works with my version.)
--- clarification
I'm not too sure how to describe the problem better. I was thinking to write a test widget next to see how I can reproduce the problem and then post that and eventually fix it. 8-)
The default layout function that the internal Qt layouts make use of require a lot of coding. I would like to avoid having to copy/paste all of that because for maintenance, it makes it close to impossible.
--- today's findings
As I needed to tweak one of the widgets, I decided to add a VBoxLayout and make it work.
I actually found the problem... One of the widgets in my tree is a QScrollArea and that sizeHint() returns (-1, -1). Not exactly what I'd expect but... whatever you put inside that widget has better know how to compute its width and height or else... it fails.
Looking at the code closely, I could actually compute the width by using the widest width found. Once I used that, the widget would appear (and it actually resizes itself as things change in the list, kinda cool.)
This being said, my earlier comment about having a tree of widgets that auto-resize themselves stands. From the root up to the parents of the leaves in your tree, all of those widgets will need a valid layout. Once I added one in the top widget it resized itself and its children properly (well... in my case up to the QScrollArea, the rest required a bottom to top resizing. Funny how that works!)
--- ah! ha! moment (or: what you find reading the implementation code!)
Today I bumped in another problem which just needed the correct call... I just couldn't find anything worth it in the documentation.
All the objects have a layout now, but a certain parent would not resize properly. Plain simple.
I had a call to the parent as following:
// changes to the children are changing the geometry
parentWidget()->updateGeometry();
Yeah. The docs says that's what you have to do. Nothing happens at all with that call. No idea what it's supposed to do, I did not look at that function. It never did anything for me anyway.
So... I looked at the layout to try to understand how it would send the info up/down. I did not see much except for one interesting comment:
// will trigger resize
This is said of the SetFixedSize mode. To reach that function you need to make the layout for update. Ah! Yes... the layout, not the parent widget... let's try that instead:
parentWidget()->layout()->update();
And voila! It resizes correctly in all cases I have. Quite incredible that the widget updateGeometry() doesn't trigger the same effect...
Although it's possible to do what you want it sounds like the problems you are having are because you're using Qt in a way that it's not meant to be used. Why do you need separate widgets for each key represented on the keyboard?
I see two options, both of which are better in some way:
Use QGraphicsScene and QGraphicsView.
A single custom widget that uses custom drawing to display the keyboard (and likely uses hover for hints).
The first option is probably better. Your keys could then be represented by QGraphicsSimpleTextItem's or even a QGraphicsSvgItem. It also provides a number of standard layouts or you could choose to write your own layout. By default you can use the keyPressEvent or mouseReleaseEvent to respond to user interactions.
I'd highly recommend you take a look at the QGraphicsView examples to get an idea what you can do.
If you go the second route you'll need to record the different key locations so you can respond accordingly as the user moves the mouse around, clicks, etc.
This won't help you with your immediate issue but I wanted to show you a keyboard I made using standard layouts and buttons. It's not perfect and it still won't help you with an enter key that spans two rows but it's not bad. It's resizable too by resizing the window, although I'm not sure if that will be apparent from the images below as SO may be scaling them. (you can view the actual images by opening them in their own tab)
Anyway, this was done using only Qt Designer with no manual coding. It consists of a top level vertical layout with 5 horizontal layouts in it. The buttons are then inserted into one of the 5 horizontal layouts. The size of the keys can be controlled by setting the horizontal and vertical size policies to "ignored" for most of the buttons and then horizontal "minimum" for buttons that you want to be wider. Things can be tweaked by setting min and max size restrictions to buttons. When resized, the buttons will not maintain their relative proportions though, that would probably take some custom programming.
The styling in your example could be approximated pretty well using css style sheets and background images. Still not a minor effort but you should be able to get most of the way there without custom layouts and buttons.