If I have two Rectangles side-by-side, and I want to position an object (text or numbers) at specific points within each rectangle, can I use the pixels taken from the size as a positioner?
In this example the Rectangles are width:100 height:100,
What I would like to do is place my first object at width: 2 and height: 2, and another object at width: 23, height: 23
My Question Is
Can I use the pixel size of a Rectangle to position children of it?
If I understand your question fully, you want to set one or more items(text/numbers ect) at certain points within a rectangle?
Personally I am unsure if this is possible?!, see the link for all members of QML Item/Rectangle;
Item QML Type
Without knowing your use-case, if I wanted to add multiple items within a rectangle, I would use either a Grid,Row or Column for adding multiple objects to a rectangle, I have linked below for each of them. Please remember these are just positioners (as with eyllanesc comments) if there is specific place you want them too be, use a Repeater with a model (also linked) and for what use? Let me know if that's the case and I might be able to help a little more!
QML Grid
QML Row
QML Column
QML Repeater
Thanks!
Related
I want to make something like a gridlayout but the layout must decide how many elements can be fitted in a row, and when the row is full continue with the next row.
QtGridLayout also fixes the columns width.
I want to something like this (this pictures was manually organised in Horizontals and verticals grids)
When the image size changes one of the buttons goes to first row.
((In this compositions both images looks with the same size, but actually second one is wider than first one).
Some one answer this question but remove it, so the credits are for my unknown friend.
Qt have an example named Flow Layout Example for a widget based form and another for Graphics View widget.
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 hope to create a "NEW" listview like QML Exmaple with native Qt classes.
Exactly I want to make a listview which works like below.
It looks like a QML example but slightly differs. QListView has a limitation for it's layout, right? I want a hint for overcoming the problem.
You'd want to use GridView instead of ListView. That'll get you a step closer to making your UI look like what you have designed. However currently Qt Quick only supports fixed cell sizes of grid items, which means you won't be able to expand the cell size of just one item. All you can do is set up the cell size to fit the expanded item so that every grid item will take up as much space as it could possibly need. Then you can alter the dimensions of each item without worrying about fitting issues.
I'm working on a simple widget system, and I'm implementing some containers right now.
Here's the situation I find myself in:
I have a Widget base class, a Container class, which is a widget that can contain other widgets, and several widget sub classes like Button.
I have two types of container: Container itself, which positions children absolutely, and Box, which will stack widgets next to each other, either horizontally or vertically.
Each widget draws itself at x=0, y=0. Therefore, containers need to add an offset to the drawing context before the widgets are told to draw themselves.
Each widget does its own hit testing based on its x/y position.
So far, it works fine. But it falls apart now that I'm implementing Box: What I do is that I overwrite the drawfunction inherited from Container to draw them all in next to each other, instead of based on their x/y position. Quite simple.
But event handling is totally off now, as the widget's x/y position has become meaningless.
I think I have two options:
Have the widget do hit testing at position x=0, y=0, like drawing. Then recalculate the mouse position to match that in Container.
Make each layout set x/y for its children, and make children draw themselves at their x/y position again. No more offsets for the drawing context
The first one is a bit ugly, I think. The second one is pretty complicated to implement, since I need to react to position changes in widgets.
How to other widget systems like Qt, Gtk and wxWidgets generally tackle this? I've looked at the source of some of these, but can't quite figure that out, it's too sophisticated. I don't have any resizing or packing issues to consider.
You are trying to implement your own layout system. You should expect it to be difficult.
I would advise against the first method. The x,y coordinates of a widget are not only used by the widgets themselves, but by anyone outside of the container who wants to do something with the widget.
The second solution is what I've chosen to implement custom widgets made of several smaller widgets and it's not that hard to put together if you don't want too many features.
Just get the widgets when they are added to your container, set their position to the current free spot, and move on to the next.
Hi i'm trying to get a photoshop-like behaviour for my QGraphicsScene
The grid in the background should not resize with the call of scale. And I must be able to save the picture with QPixmap::grabWidget(view) but without the background grid. I can probably do it with removing the background layer just before saving the picture, but i'm not sure if its cleanest way to do it.
Any ideas ?
thx.
Question 1
The grid in the background should not resize with the call of scale.
Use the QGraphicsItem::ItemIgnoresTransformations flag.
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.
In order to set this flag use the setFlag function when creating the grid item.
Question 2
I must be able to save the picture with QPixmap::grabWidget(view) but without the
background grid.
Call the hide function on the grid item before calling the grabWidget. After you have grabbed it you show it again by calling the show function.