This screenshot
shows a pretty simple implementation of a treeview where I used a custom treecell made up of a flowpane with 5 labels. The flowpane extends to the edge of the treeview (highlighted unused flow pane space in red).
What I want to be able to do is resize the labels to take up all available flow pane space. Ideally each treecell(label in the flowpane) would be able to be independently resized. I haven't been able to do this in the custom tree cell and/or cell factory because the width of the flowpane isn't known at creation time (at least I haven't been able to determine it).
As far as I have been able to determine the tree cells aren't directly available through the treeview. I have attempted to save the cells in the cell factory at creation for use at a later time but there are 48 cells created just to show the 5 that are shown in the screenshot and I'm not sure which of those 48 represent those on the screen (presumably the last 5).
So I guess the easiest way to ask the question is, how can I access the flowpane of the tree cells (and by extension the labels) so that I can calculate and set the label widths?
Related
i'm struggling with a vertical box i added a transition to, it stays at the back of the other nodes like label and imageview. i tried using toFront() but it didn't work. also i tried using .setStyle("-fx-view-order: [number]") but i was lost a bit in what the numbers represent exactly is it the order of nodes ascending or descending.
#1
vb.setStyle("-fx-view-order: 0");
img.setStyle("-fx-view-order: 1");
didn't work
#2
vb.setStyle("-fx-view-order: 1");
img.setStyle("-fx-view-order: 0");
didn't work
The easiest way to get a Node to render on top is to move it to the end of the child node list for its parent Node.
Note the documentation for -fx-view-order mentions: "The parent traverses its children in decreasing viewOrder order." To me that means higher view order is behind (drawn first) relative to lower view order. However, this is all relative to the parent node, not the Scene. Give us a reproducible example of what you are doing.
Also, what version of JavaFX are you using? -fx-view-order was not in JavaFX 8 (JDK 8)
https://docs.oracle.com/javase/8/javafx/api/javafx/scene/doc-files/cssref.html#node
So I currently have got a custom widget, and I want to add them to the main window after clicking a button. I would like to add them all to one fixed position first and then I will be able to drag them wherever I like. I am able to create and display these custom widgets with help of QHBoxLayout or QVBoxLayout, but in this case they will not be in the same position after I create them. Any help will be appreciated!
As the names suggest, the QLayout classes manage the position and geometry of the items added to them. You cannot move (eg. drag) an item out of a layout w/out first removing it from the layout (QLayout::removeItem() and derivatives). For example when you drag a toolbar or dock widget out of a QMainWindow it goes through all sorts of machinations to remove it from the MW layout, change the widget's window flags, remember the old position in the layout, and so on. And the reverse to dock it again.
To do what you describe (drag widgets arbitrarily around a window) you would need to not use a QLayout and position the widgets manually by specifying a QWidget::setGeometry() for example. After initial position, and assuming the user has some way to grab the widget (title bar or drag handle you made, etc), you'll probably still need to manage their positions, for example if the main window is resized (if you care about keeping them contained). Essentially you'd have a bunch of separate widgets acting as individual windows and probably need some way to keep track of them.
I don't know what kind of widgets you're talking about, but one option may be a QMdiArea which lets the user drag windowed widgets around, tabify them, save/restore state, and so on.
For more flexibility you could also look into the Qt Graphics Framework. The graphics scene has a lot of features for user-movable items/widgets, keeping track of them, and so on. It is probably the most flexible method overall, and you can also use regular QWidgets inside a graphics scene.
A couple other Q/A about arbitrarily positioning widgets (I'm sure there are more to be found):
QPushButton alignment on top another widget
How to keep Push Buttons constant in relative to change of Label Size in PyQt4
In graphics view m setting scene in that adding objects (by dropping ), i can move these items by mouse, when i moved one object on another object moved object should be transparent. how can i make it?
I don't believe you actually want full transparency since it will make it impossible to visually recognize the transparent object later on. Reduced opacity - yes.
As for your question: each item inside your scene has a bounding rectangle (or other type of bounding area). You can easily get it by calling boundingRect() of your item. The returned QRectF has (just like QRect) has the bool QRect::intersects(const QRect &rectangle) const function, which takes another rectangle and checks if a collision is present.
Whenever you move your mouse while dragging an item you need to iterate either through all or just a subset of all items in your scene (by subset I mean just the items in a specific region to increase the performance) and check for collision. If a collision is detected, you can alter either the item you are dragging or the item underneath it.
Of course to make sure that one item covers another one you also need to check the Z value. The easiest way to do that is if you keep all currently not being dragged items at the same Z level and then, whenever you drag one, increase it's Z level by one so that it is "above" the others.
The documentation for the QGraphicsItem::ItemIgnoresTransformations flag says
The item ignores inherited transformations (i.e., its position is still anchored to its parent, but the parent or view rotation, zoom or shear transformations are ignored). This flag is useful for keeping text label items horizontal and unscaled, so they will still be readable if the view is transformed. When set, the item's view geometry and scene geometry will be maintained separately. You must call deviceTransform() to map coordinates and detect collisions in the view. By default, this flag is disabled. This flag was introduced in Qt 4.3. Note: With this flag set you can still scale the item itself, and that scale transformation will influence the item's children.
Of course I have read the QGraphicsItem details, the QGraphicsScene details, the QGraphicsView details, and the Graphics View Framework.
There are also several questions about the ItemIgnoresTransformations flag like Fixed size QGraphicsItems in multiple views?
But I still do not understand the sentence in bold face. What does it mean ?
The problem that rose this concern is described in PyQt: Moving multiple items with different ItemIgnoresTransformations flags, but maybe this question was too long, or too pyqt oriented at first sight. And it was more about moving items. So here I'm trying to better focus.
Imagine situation that parent is rotated 45 degrees or even have some sheer. Since current item ignores this transformation it stays strait (not rotated).
Now ask question how this impacts on item size and position? Parent may maintain geometry of item (for example by using layout) but it doesn't take into account this flag, so some geometry (which is in parent units) will be set but effectively items scene rect may appear different since item ignores transformation and it is not rotated squeezed zoomed as a parent.
So from parent point of view geometry has some value but form scene point of view it is different.
It would be best if you try to see how it works in practice It is hard to describe problem clearly.
I created a sketchUp plugin that draws a wall (with lenght, width and height).
Now I would like to insert a "window" in that wall (fixed length, width and height, depending on the wall). How can I:
Create but not yet draw the group containing the window. Link it to the current mouse position
Constrain the current mouse position to the front plane of the wall I drew before
When the user clicks, the window is inserted and the group is shown
The easy way to do it, that doesn't fulfill your request 100% - but do use existing SketchUp conventions, is to create a component definition and then use Model.place_component to activate SketchUp's native tool to position a new component instance.
In order to fulfill your question 100%:
A Group is an instance. You cannot create one and not place it in the model. You can create it in step 3 when the user clicks. (Though, a window sounds like a candidate for a component since you usually have multiple copies of the same window type.)
You cannot constrain the mouse cursor itself, but if you implement a custom Tool and make use of the InputPoint class you can selectively determine what is a valid insertion point when the user clicks. You can also draw virtual lines and polygons to the viewport to give a preview of your window.
Profit!