I have tried to search on the internet and here as well, without success though. I am using Qt 4.8.2 and design my app in the Designer, then I write code in VS2010. I would like to show a chart on the application window, e.g. like http://www.infocaptor.com/user_help/help_img/dashboard_line_chart_screen.png , based on some data that are created by the app.
In the Widget Box of the Designer, I can't find any widget related to drawing. So I tried creating a QTextEdit and drawing on that using QPainter. However, this does not work. I can draw on the whole appwindow, but not just on the text edit. So the question is: what widget can be added onto the app window in the designer and that is going to allow me to draw on it using QPainter?
I'm eluded as the documentation says specifically that QPainter can draw on any QWidget which a QTextEdit is...
Any help is much appreciated,
Daniel
The function of "drawing" is tooo complex/unspecific to be included as a specialized widget. You'll have to create it yourself and implement the desired drawing functions.
Here is an example which you can learn from, the scribblearea class could be pretty much what you are looking for. In that case you can copy it to your project and use in in the Qt-Designer by promoting a widget to this class.
Related
before I used Qt and customized my own Widget which is inherits from QGLWidget
i used OpenGl in standard projects and free glut.
by doing this, I used glutBitmapChracter but now in Qt there is no need to manage windows because I created customize widget with gui.
so how can I draw text on the widget?
if I want to include the free glut and use glutBitmapCharacter I nedd also to init the glut and im getting confused?
is there any other way or do I have to use external library?
You are using a QGLWidget and want to draw 2D text on top of the 3D scene?
glutBitmapCharacter should still work in a QGLWidget, just like other GL library code. I do not think you need to call glutInit to use the GLUT character drawing functions.
Or you could use the Qt 2D text drawing methods (QPainter) to draw text on top of your QGLWidget. A Qt book or online documentation will explain how to do this. (I have the books on Qt programming by Blanchette and Summerfield, and can recommend them.)
Hope this helps.
I have found a really neat custom widget for Qt and managed to incorporate it into Qt Designer. I would now like to create a customer widget in designer by placing 32 of these LEDs into a new widget in Designer, then add some functions to it such as giving it address and passing data into it that will then illuminate patterns in colours according to the passed data.
My questions are:
Can I do this? I have placed 32 LEDs on to a new QFrame widget in designer and named the LEDs 0-31, but am at a loss as to know what to do next.
Is there a tutorial anywhere for this? I have found loads of hits on google for creating custom widgets for designer, but not using designer.
Please bear in mind I am not a good Qt programmer, I write embedded code for micros in C and am really not good at object orientated code; I can just hack together relatively simple programs for test and measurement. I need something that will hand hold me through this.
http://doc.qt.io/qt-5/qtdesigner-worldtimeclockplugin-example.html
This seemed to be the kind of thing I wanted, it seemed to look like someone has placed widgets on a screen to create a new widget, but it seems to keep referring back to Creator.
Maybe I am trying to do something impossible. Maybe I have to place this new LED in creator with code?
Many thanks for any pointers.
Yes, it is. A Designer plugin basically consists of 2 Parts:
The Widget that you want to add to the designer
The plugin itself that provides information about the widget usw.
You can simply create the widget with the designer, add the QDESIGNER_WIDGET_EXPORT macro and thats it. Create your designer plugin to load this widget and it should work.
Note: Since you mentioned your not very experienced, you should try to follow the Custom Widget Plugin Example. Once you understood that one, it's only a small step to your designed plugin.
I'm comfortable with C++ but brand new to Qt. I apologize for my ignorance as I'm sure this is a very simple question. I'd like to make a custom clickable widget, basically a push button that is just a black square with Qt designer, but don't have any idea on where to start.
EDIT: after fumbling around I think I'm an epsilon closer.
I created a black_box.png file. In the resource browser I created a new resource and prefix, and added the black_box.png. Any advice from here?
You have a few options for what you want to achieve.
You can use custom painting to draw a new button that subclasses QPushButton, this is reasonably involved and provides a huge amount of flexibility to build it to your requirements.
You can use Qt's stylesheets mechanism to style it, you can get more information on it here: http://doc.qt.io/qt-5/stylesheet.html
Or you can set a QPixmap of your image to be a button icon, and size your button to match it, there's a good answer on how to do this on this question: How to set image on QPushButton?
I'd like to implement a sidepanel in my Qt window. I search something like the one that is used in the Visual Studio (see below).
Important notes:
The widgets don't have to be moveable
resizing should be possible
each widget should be clearly separated from the other layout
Does anyone have an idea how I could build such a sidepanel? (Maybe there even exists a library)
Or does anyone know a project which uses Qt and some kind of sidepanel?
One option would be to use QDockWidgets. That's the type of thing they are intended for inside a QMainWindow.
You can put toolbars, QTreeViews and QTableViews (or related) widgets inside your dock widget to simulate the screenshot you posted.
For an example usage: Dock Widgets Example.
I want to play a video (with sound) in a simple GUI with "play" and "stop" buttons etc. There are classes and widgets in Qt's Phonon module for doing that, and several examples. OK, so that seems to be simple.
But now I need to draw some custom graphics (that depend on the current time in the video) on top of the streamed video image. I have not found anything about this in the Qt documentation. What's the canonical way of doing this? Do I just create a custom VideoWidget widget and override its paintEvent? In another question here, some guy seemed to have trouble with this.
Any pointers would be appreciated.
Use QGraphicsView and QGraphicsWidgets. You can put your Phonon::VideoWidget inside a QGraphicsProxyWidget and it becomes usable as a QGraphicsWidget.
For custom overlays, inherit QGraphicsWidget and override the paint function to draw your custom widgets. You can add them to your scene and they will appear on top of your video widget.
Your solution cannot work because you cannot add a QGLWidget to QGraphicsProxyWidget. Please look at
http://doc.qt.digia.com/qt/qgraphicsproxywidget.html
Note that widgets with the Qt::WA_PaintOnScreen widget attribute set
and widgets that wrap an external application or controller cannot be
embedded. Examples are QGLWidget and QAxWidget.
Please correct me if I'm wrong.