tkinter custom widget collecting - python

I'm searching for a tkinter custom widget collection that I can include in a application designer I'm writing in 100% Python but haven't had much luck yet. I figured out a way to do a table for instance, but would like to save myself the work if there's a good implementation out there.

I found a couple of packages for pure Python custom widget creation with a little more searching online. One is Python megawidgets, at pmw.sourceforge.net, which, according to their documentation:
"is a toolkit for building high-level compound widgets in Python using the Tkinter module. It consists of a set of base classes and a library of flexible and extensible megawidgets built on this foundation. These megawidgets include notebooks, comboboxes, selection widgets, panes widgets, scrollable widgets, and dialog windows."
A different approach is writing custom widgets yourself using the Widget Construction Kit, at effbot.org/zone/wck.htm. This provides a base Widget class with primitive drawing methods, such as for borders, text, and colors, along with a basic but complete set of event definitions for binding your event handlers to your custom widgets. It has some good advice on doing animated widgets, such as drag and drop.
If anybody knows of any other packages of widgets or construction toolkit APIs, feel free to post it here. Developers will appreciate having a larger selection in a single location.

Related

Python - Custom styling in wxPython

Is there some way I can create custom styles in wxPython? I searched all the docs and websites referring to wxPython styling and could find nothing. Do I have to create the custom style using the wxPython canvas?
wxPython uses native widgets in its core widgets as much as possible. Most of the widgets are going to be "native" to the system you are using, so unfortunately you can't fully manipulate how the control paints itself.
Sometimes, you can modify widgets via the methods mentioned in the documentation, such as using SetBackgroundColour() or SetForegroundColour(). Depending on your OS's widget, they may or may not work.
The other option is to use the wx.PaintDC, wx.ClientDC, wx.WindowDC, wx.ScreenDC and/or wx.MemoryDC to draw custom widgets directly.

How to Build a Custom wxPython Custom Menu Widget

Background:
In recent days I've been experimenting with building many ordinary widgets from scratch in wxPython using the PyControl method of building custom controls as a personal challenge. However, I've hit issues when building a custom menu widget. By this I mean I am envisaging a button that when clicked on yields a drop down menu of options/commands etc.
Question:
What is the best way of achieving a completely custom menu widget in wxPython? Ideally I'd like to use only original code (i.e. as much as possible handled directly in the code). An ideal answer would include a runnable code snippet if possible.
Thanks for any help!

Custom Qt Widgets with python for Qt Designer

I am trying to write a custom widget for the Qt Designer using only Python. I was following a couple of tutorials I found online but none of them were working or anything close to what I would call to be a minimum working example.
So my questions are:
What steps are involved to make a a custom widget appear in the Widget Box of Qt Designer?
If you can spare the time: Please provide a minimum working example (like a widget with a label in it saying "A truly minimal working Qt custom widget example").
Or is it maybe not possible at all to include a custom widget using only python?
There are very few examples available on how to make a custom widget in pyqt. I wrote this article with a working example: Making a Custom Widget in PyQt
Here is the answer to your question #3: How do I use promote to in Qt Designer in pyqt4?
I am using PySide and it works the same way. This method works directly with your Python custom widget code. You do not need to write any separate plugin code.
After you have promoted your custom widget, you can right click on it and add your signals with "Change signals/slots..."
I would recommend putting all you widgets in a YourCostumWidgetsPack.UI file, and then when you load this file in Qt Designer, in addition to the UI you are working. It will load all your custom widget information.
I found this article to be your answer: https://doc.qt.io/archives/qq/qq26-pyqtdesigner.html
But, I haven't been able to install it in Qt Designer though :D

Trying to learn PyQt with knowledge from Tkinter

Maybe I'm jumping into the deep end, but I'll give it a shot.
Here are some useful features of Tkinter:
The Tkinter Canvas widget is an object oriented drawing canvas. The elements of the drawing are essentially widgets themselves, as they can be moved, modified, and bound to events.
Tkinter uses bindings to trigger callbacks. The event is passed as a string. Custom events can be easily created with event_generate.
Tkinter has the after method, which waits for a specified amount of time without freezing the GUI.
Tkinter has predefined fonts like TkDefaultFont, and colors like systemButtonFace, which are dependant on the system.
My questions are:
What are the pyQt equivalents of these features (especially the bold ones)?
How can I "bind" elements of a widget (e.g. the label of a checkbutton only) to an event?
In Qt and PyQt events are called signals and you bind to them using slots (docs here). Generally speaking what you do define a slot with an # decorator.
class WindowImpl (QtGui.QMainWindow, Ui_TremorMain, Ui_Graphs):
def __init__ (self, buffer, parent = None, configuration = None):
# do some initialisation here (not GUI setup however)
#QtCore.pyqtSlot(int, name="on_confSelectorCombo_currentIndexChanged")
def confChanged (self, newConf):
# do some stuff here to handle the event
The above would be triggered on the currentIndexChanged event of an object called confSelectorCombo. The setup of the confSelectorCombo is done in the GUI builder or Qt Creator as Nokia has decided to call it. This really is what you want to use to get started. There's tutorials here on using Qt Creator. Obviously you'll want to go through the docs and see what signals are emitted by which widgets.
As for the font stuff all I know is what it says on the docs:
If you have not set a font for your application then the default font on your
machine will be used, and the default font can be different on different
machines. On Windows the default Windows font is used, on X11 the one in qtrc
can be used. If a default font can’t be found, then a font specified by Qt
will be used.
The QStyleSheet and QStyle act as proxies for changing the appearance of widgets (QStylesheet,QStyle).
As for making the application wait I found this
QTime dieTime = QTime::currentTime().addSecs(2);
while( QTime::currentTime() < dieTime ):
QCoreApplication::processEvents(QEventLoop::AllEvents, 100);
There is also QThread.sleep() (docs), depending on what kind of an effect you want. Probably also worth looking at the threading support over at Qt docs
Overall in finding information about how to do stuff in PyQt I have found it surprisingly useful to look at the Qt documentation and then just writing the stuff in Python. 9 times out of 10 this works. On another note, it's probably also worth looking into PySide which is another python Qt library. I've haven't used myself before as it has been in the works previously but I noticed that they had released a 1.0.6 version.
UPDATE
Just to reiterate Luke Woodward below, you can use QGraphicsScene and QGraphicsView to render stuff in an object oriented way. The QGraphicsScene doesn't actually render anything it just a scene graph, the QGraphicsView is then used to render the contents of the scene graph. For low level drawing there´s also QPainter - there's a basic drawing tutorial here. It's also worth looking at QGraphicsItem which is the base for all graphics items and
includes defining the item's geometry, collision detection, its painting
implementation and item interaction through its event handlers
docs here. The Context2D provides an HTML canvas (if I'm not mistaken through the use of WebKit). The canvas itself only has a changed slot, but any objects you place on the canvas will/can have more slots. There's a fairly complete looking tutorial on Context2D and Context2DCanvas here. For an explanation as to why so many different ways of rendering stuff, you'll have to ask someone else. My two cents is that is has something to do with the fact that Qt is supposed to work everywhere and Trolltech and later Nokia wanted to provide lots of choice. Luckily the docs are really good.

PyQt4 Custom Widgets

Are there any good PyQt4 custom widgets like at Qt-Apps.org?
I would like to start making PyQt custom widgets but online resources that I find don't seem to be clear
For example, Trolltech's and Zetcode's don't seem to be related in any way at all.
Thanks for any input :)
There should be PyQt examples of all C++ Qt examples in your PyQt4 distribution. I have them here: /usr/share/doc/python-qt4-doc/examples. Theye are quite good for the start. When you understand them, it should also be fairly easy for you to port some C++ examples to PyQt code or turn C++ custom widgets to C++.
online resources about PyQt aren't really that rampant, so any information/projects would be welcomed. Don't hesitate to post links to your upcoming widgets or anything else.
I would be really glad to work on that with you as i'm learning more about pyqt as well.
Are you looking for tutorials on making custom PyQt widgets, or looking for a library of them?
I've been developing a library of reusable custom widgets if that's what you're looking for - at somepoint will be getting to the tutorials, but they aren't there yet.
Check out projexsoftware.com, specifically the ProjexUI framework:
http://dev.projexsoftware.com/projects/projexui
http://docs.projexsoftware.com/sdk-reference/projexui-sdk
In looking at it, I'll need to get some images up there...but there's a Calendar widget, Gantt Chart, View plugin system, Node view, Chart widgets, along with a number of extensions to the base Qt widget classes.
Also the easiest way to see the majority of the widgets is in the Qt Designer - so if you have it setup to work with PyQt plugins, wherever you install the projexui library you can add the /path/to/projexui/designer/build to your PYQTDESIGNERPATH and it'll load designer with our plugins.

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