I am using QTextEdit to implement an editor. One of the requirements I have is to add fixed position text on top of an image.
For example:
I have an image of dimensions: 300x300. I need to add text beginning at the location (20, 20) of the image and ensure that the text does not flow beyond the width of the image.
Something like below:
I am thinking that if I can add a QGraphicView, I can add the image and position text appropriately. Is this possible? Is there a way to introduce a graphic element into a QTextedit? If not, what is the right approach?
Is there a way to introduce a graphic element into a QTextEdit? If not, what is the right approach?
You could look at this the other way and add the QTextEdit to a QGraphicsScene. The graphics scene provides a QGraphicsProxyWidget to add standard Qt widgets.
Therefore, you could create a QGraphicsScene and QGraphicsView. Add a QGraphicsPixmapItem for the image and add the QTextEdit item with a call to QGraphicsScene::addWidget, which returns a QGraphicsProxyWidget, allowing you to position, scale and resize the widget.
Alternatively, you could start with a QGraphicsItem, inherit from that and create your own object which encapsulates the image and proxy object of the QTextEdit.
There are other ways of tackling this too, but I'd probably go for the custom QGraphicsItem. It also depends on your specification, but you can add text items in a graphics scene, without the QTextEdit, though you'd probably have to implement the editing feature, if this is required.
Related
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
I have a Qlabel with image as rich text and some other Qlabels on top of that as in the picture:
although I sent the Qlabel with image to back but when I run they appear as follows:
is there anyway to fix this?
Make the text labels children of the label containing the fade. Also I can not see any layouts. Did you use layouts? You could also put the fade on the widget by implementing its paintEvent(). All other widgets will be displayed on top of that.
Try right clicking the image label and clicking the send-to-back option. That might work. That should send the QLabel behind the other elements even though they appear as though they are already in front.
I am trying to place a .png image(firm logo) at a specific point(coordinate). I've put several buttons, one after another, and now I want the image to be displayed just below these buttons. The code below should do the trick, but the coordinates are simply not working.
//QLabel myLabel; QVBoxLayout *layout; // class members, initialized with 'this'
QPixmap pixmap("v.png");
myLabel.setPixmap(pixmap);
myLabel.setMask(pixmap.mask());
myLabel.setGeometry(QRect(312, 454, 21, 20));
layout->addWidget(&myLabel);
How should I modify the code to simply include this image, possibly at a specific coordinate (just as with QPushButton)? Note that commenting out the last line removes the image, but, even when the image is shown, the buttons cannot be clicked (and they are not part of 'layout') Please provide code that would achieve image positioning with given coordinates.
QLayout is a controller which position widgets added to it. That is why it has no any sense to set coordinates to a widget and then place it to a layout. The layout will change the widget coordinates as soon as the widget is shown.
Futhermore, if you ask how to set certain position in coordinates, you shouldn't use QLayout at all, because it will change any position you set.
QPixmap pixmap("v.png");
myLabel.setPixmap(pixmap);
myLabel.setMask(pixmap.mask());
myLabel.setFixedSize(21, 20);
myLabel.move(312, 452); //ensure that this coordinates are in you widget
myLabel.show();
You will have to either show the label or put it in a layout or make sure it was given a parent in the constructor.
myLabel.setParent(parent_window)
The setParent method might also need you to show.
myLabel.show()
or
layout.addWidget(myLabel)
I have a full size QGLWidget which paints the application background using QPainter (might change to native openGL commands in the future).
On top of this QGLWidget I use QWidgets (non-GL) for the user interface elements. These are, for example, QLineEdits and QPushButtons. I put them into a custom painted QWidget which uses semi-transparent background painting. The paintEvents of the QLineEdit and QPushButton are overwritten and use semi-transparent backgrounds, too.
The whole UI should look like the following (This is a screenshot where I disabled OpenGL and used QWidget instead of QGLWidget for the background. Note the semi-transparent top bar which also draws a shadow (within its own region)):
When the QLineEdit has the focus, it should have a higher opacity but still not fully opaque:
So now, with OpenGL enabled (The background then is a QGLWidget), the semi-transparent widgets above don't paint on top of the background but on (it seems to be) uninitialized data. The image shining through the top bar is sometimes the whole window itself and sometimes other windows currently being on my desktop.
This currently looks like the following (In this screenshot, the data on which the semi-transparent painting operations are painted on seems to be an image of the widget itself, having an offset.):
When I wrote text into the line edit (here: "This is some text which has been there before!"), removed it and set the focus back to the background widget (so the magnifier icon and the placeholder text appear), the previously painted things still shine through (Note that the visible border should not be visible anymore, but also still shines through):
So the problem is: Instead of being painted on top of the underlying widgets, the semi-transparent widget is painted on top of the old results, initially being something like "uninitialized memory".
Why does this happen? How can I solve the problem?
Things you should know before answering:
The background scene is a composition of tiles which are rendered off-screen. So it can be painted very fast and repainting of the background for every little change of the overlay isn't problematic.
The top bar is a custom QWidget with manual painting and arrangement of the contained two widgets (the button and line edit).
The two widgets overwrite the paintEvent, only draw their own (semi-transparent) background when they have focus and don't use frames already provided by Qt. So the white border in the second screenshot is drawn in my custom paintEvent.
I want the background and the composition of overlay widgets to be separately implementable. The background is an AbstractMapView which has some concrete map view classes. The whole window is an AbstractView (there are multiple concrete views, too), which contains both a concrete map view and the overlay widgets, composed in a way itself decides. Therefore, I don't want the logic of the overlay widgets to be part of the underlying map view. (I hope you understood this, as it is a bit complicated.)
This sounds like an issue where the GL content (i.e. your background aka the QGLWidget) is not in the Qt context. While I'm not a pro on GL painting with Qt, you may want to look at this discussion regarding GL painting and a QLabel for some direction/potential hints.
http://www.qtcentre.org/threads/40335-QLabel-on-top-of-a-QGLWidget-background-issue
In short, we here at the office use OpenGL painting and offscreen rendering of maps and it's very important to make sure Qt is aware of the pixels so your foreground widgets can have the semi-transparency applied to their backgrounds.
The particular product we use also renders the map in tiles and supports providing the GL output in a buffer (i.e. it's call a snapshot and is provided as a bitmap) at which point we use the paintEvent of a regular QWidget to paint the buffer so that the painted pixels are in Qt context.
You can define a Qframe with Qt::SplashScreen flag as the search box and set its opacity. Put your widgets inside it such as the search textbox and positon it where it should appear on the mainwindow. It will also be a good idea to reposition it as the mainwindow is moved or resized overriding its moveEvent.
I have a QDialog I'm working with. It is made somewhat like a QMessageBox. I noticed that the size of the QMessageBox (and the size of its label) depends on the size of the message displayed.
How would I make the size of my QDialog adjust automatically like a QMessageBox? Presently my QDialog contains a button box and a label, and the QDialog is layout Vertical.
(I know I could just use the message box directly but eventually I will have more complex dialogs.)
Automatic solution:
Use layouts and set size policies to QSizePolicy::Expanding. In QtDesigner, once all your children are placed on your QDialog, then click on the Adjust Size button next layout ones. Your QDialog will be automatically resized at runtime.
Manual solution:
The QWidget class has a method adjustSize that resize the QWidget to fit its content. Just call it when all children are set.
Set your dialog to be expanding, and very small. Then, be sure to set your message before showing the dialog. When shown, it will try to find its proper size, based on the size of the objects it contains. (This happens recursively, so if the dialog isn't the direct parent of the label in which you show your message, make sure everything between the label and the dialog is set to use layouts.)
A TIP : if you try to use "adjustSize()" function when dialog is hidden, it may not be works fine. It would be better to use it after the "show()" function.