I ran in to a problem where I was doing property animations on widgets but they animation positions would seem to get overwritten on the next layout pass. The widgets would seem to jump position right at the beginning of animation, making it look bad. As a result I thought maybe if I wrote my own layout code I could have more control over things.
What is the easiest way to write a custom layout in QT? I tried following the steps in the "Manual Layout" section of the documentation: http://doc.qt.nokia.com/latest/layout.html#manual-layout However I seem to be hitting a crash when I try calling setGeometry on the child widgets. Also, the docs seem to conflict with the "Manual Layout" saying to call setGeometry from within resizeEvent and the resizeEvent doc saying not to do that.
I suppose I could just write a real layout class. Doesn't look like too much code. But I'm wondering what the easiest/simplest way to get custom layout is.
I think this might work.
Start with widget A positioned entirely outside of the parent widget. Do not add that widget to the layout. A's geometry may well share an edge with the parent.
Create a dummy widget D that forwards A's sizeHint() but does nothing else. Put it into the layout.
Animate widget A toward the geometry of widget D.
Swap the widgets in the layout (remove widget D, add widget A).
If widgets A and D are of your own making, then you should be using the PIMPL idiom. If your widget has no child widgets, swapping the widgets would be trivial -- swap the pimpl pointers. The widgets themselves don't have to be swapped then. DO NOT derive your PIMPL class from QWidgetPrivate, not that it's supported anyway, but I've seen code that does it. Not a good idea.
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I'm implementing a login screen. It has a centred Column containing a TextField for entering an email address and a number of buttons for social sign-in. When a button is pressed, the Column is rebuilt with a CircularProgressIndicator (spinner) added at the bottom. I've wrapped the spinner in a custom widget that manages a ScaleTransition animation. That works OK, but the Column grows and shifts up to accommodate the final full size of the spinner immediately instead of moving smoothly with the animation.
I also wrapped the Column in an AnimatedSize widget using the same curve and duration as the ScaleTransition, but it hasn't helped. The root of the tree is a Consumer of the state that triggers the addition of the spinner so the animations should both be starting together. Maybe the the spinner needs to be permanent for this to work, but it doesn't seem desirable because its API doesn't provide a way to pause the animation. It would presumably constantly use some power to animate itself even when it isn't visible. I'm fussy about that sort of thing.
It looks like I might have to use an AnimatedList, but it doesn't seem semantically correct because the contents aren't really a list. So is there a more generic way to animate the size (and position) of parent widgets like Column and Center to track an animated size change of their children?
I have a window in mono gtk#, which has lot of VBoxes & HBoxes. These boxes contain some buttons, labels, and some other widgets also. Now I need to make this window alone to transparent.
I created one drawingArea by referring zetcode page.
But inside this drawing area I'm not able to do the arrangements of my widgets, one Move function is available, but it is not much use for me. So how do I do widget arrangement neatly inside a drawingArea?
I'm pretty new to javafx so I'm trying to learn here so please be reasonable and don't dis away my question, I really appreciate any help at all, thanks!
I would like to know how I could move an object, let's say this circle on different events, like keypress or mouseclick, mousemove, whatever.
Circle circle = new Circle();
circle.setCenterX(100.0f);
circle.setCenterY(100.0f);
circle.setRadius(50.0f);
Do I need to use that KeyFrame thing I saw on the javafx site tutorial, or how does this work?
I would not have asked this here if I weren't feeling so lost, honestly.
So to make this clear: What is the code for moving objects that I created, by using events?
EDIT: By moving it I mean, press up key and it moves up by a few pixels, transform it maybe, with another key, or click somewhere on the scene and make it move there instantly or travel there with a certain speed. I don't have to redraw it like you need to with html5 canvas, I hope, right?
I don't have to redraw it like you need to with html5 canvas, I hope, right?
Not if you are using a standard JavaFX scene graph as opposed to a JavaFX canvas.
I would like to know how I could move an object, let's say this circle on different events, like keypress or mouseclick, mousemove, whatever
There are three ways to move a Shape:
You can adjust the shape's geometry (e.g. the centerX/centerY properties of a circle).
You can adjust the shape's layout (e.g. it's layoutX/layoutY properties).
You can adjust the shape's translation (e.g. it's translateX/translateY properties).
You can think of the layout as the home position for the object; i.e. where it should normally be in the context of it's parent group. You can think of it's translation transform as a temporary position for an object (often used when the object is being animated).
If you are using a layout pane such as a VBox or TilePane, then the layout pane will handle setting the layout co-ordinates of the child node for you. If you are using a simple Group or a plain Pane or Region, then you are responsible for setting the correct layout values for the child nodes.
To listen for events, set event handlers on Nodes or Scenes.
Here is a small sample app which demonstrates the above. It places the object to be moved inside a Group and modifies the position of the object within a Group in response to various events.
I'm trying to figure out a way of using Qt Designer to make a dynamic GUI. For example, let's say I have a main window with a horizontal layout. I have a push button on one side and an empty area on the other. When I click the button the empty area will be filled with a widget that I've made in Qt Designer. When the button is pressed again the widget will be replaced with another widget that I've made in Qt Designer. Would I have to go about making all my widgets, to fill the empty area, custom widgets?
I've tried setting the parent to the empty are, but on the second change I get this
QLayout: Attempting to add QLayout "" to QWidget "t2", which already has a layout
So then I tried deleting the layout but still see the old widget underneath the new one and the layout is now messed up.
help please
Never mind, figured it out. Simple really. Use QStackedWidget and as for the UIs made in Qt Designer wrap that in a class that inherits from QWidget.
I have a grid/canvas that has an element (say an icon with an image and text overlayed) added to it dynamically via code.
Most of the time it renders correctly when added (content is aligned properly inside it),
but sometimes all the content sits in one corner.
I can remove/add/remove/add/remove/add and it will eventually do it
After a movement of the parent canvas, the element corrects itself as if the layout has been updated.
I have tried the following on Loaded and OnApplyTemplate for both the element and the element parent but it still seems to happen occasionally
InvalidateMeasure()
InvalidateArrange()
UpdateLayout()
Any ideas on why the content wouldn't arrange would be appreciated cause its driving me nuts
I'm not sure why it works for you sometimes but not others. But a grid has the inherent ability to dynamically resize itself and its contents. A canvas doesn't (you'd have to handle that manually in code).
If you change your canvas to a grid does it work? A grid has slightly more overhead than a canvas but it sounds to me like you need its functionality anyway.