JavaFX 11 has made the CustomTransfer type internal, so all of my classes which could transfer between JavaFX and SWT now break. It seems as though JavaFX now only supports the six transfer types of Text, RTF, HTML, URL, Image and File.
I can solve the problem by BASE_64 encoding my objects into a byte array and using the TextTransfer type, however, this feels very hacky and not at all the intended solution to this problem, especially since also drop accpetance information is lost because the type cannot be determined until drop.
Extending one of the six transfer types cannot work because they do not have public constructors.
What is the proper solution to be able to drag and drop a custom object between SWT and JavaFX now that the CustomTransfer type has been made internal? Additionally, as a curiosity, why did JavaFX even deprecate then internalize that class in the first place?
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I need to implement a specific text object in QEdit PyQt. I need rich objects that will content special information, capture the keyboard arrow keys only when cursor text is on these objects. They need support selection and copy / paste operations also. Outside of them, the cursor must act as normal behavior. At this time, the object does not need to show images or svg etc. Is only for capture text cursor purposes and to store specific information related with the object.
I read that I can implement a customized text object with this example:
textobject.py
but the example does not contain information about implement new html tags, how to capture focus, etc.
My questions are:
How can I add a new html tag related with my custom object for loading and saving documents?
How can I detect when text cursor is on the custom object to modify keyboard cursor behavior?
PyQt documentation says:
"Copy and Paste operations ignore custom text objects."
So is no way to implement copy / paste functionality?
How can I access to my custom object content?
I want to have specifics methods to navigate within the information contained in the object. I could save this information in another object, but I need to synchronize the information with the cursor because a document can contain many of these objects.
Context for my application: I'm developping a very specific application for blind users. I am blind myself. I need to make very specifics customizations to the Richttext area for accessibility. The goal is to develop an accessible math equation editor. For this, I need to add support for mathMl tag. I will process mathMl content inside these tags in my custom object, this part is already implemented at basic level without using any GUI framework. At this time I don't need to show the equation in the screen, I let to screen readers interact with my editor via a COM object. At this time, the equation box is functional, but I need to integrate this functionality in a rich text area. the idea is, a document can contain N math expressions that can be read, modified and saved in a document.
I plan to implement accessibility for sighted people also in the equation editor, but it is beyond my skills and is not a priority right now.
Also I need to accessibilize tables in rich text area, currently tables are not accesible in QT. Then I think to extend qt table functionality. Style elements like headings etc, does not exist in pyQt. OK, you can write a paragraph with heading style, but screen readers can't detect it. So I need to develop this functionality. I could solve it with customized objects I think.
Currently it need to work in windows only. Maybe later I'll consider other platforms.
I started to program in pyQt yesterday, but I already read a lot of documentation. I wrote a basic rich text editor to test my requirements.
I already tried to implement this application with wxPython phoenix because I've been using WX for a long time. But I couldn't implement custom text objects and I didn't find documentation about it.
If pyQt is limited for my requirements, could you recoment another gui framework?
Y could consider another languages, I chose Python because Python has many math tools like sympy or numpy, and implement user scripting functionality in the app is very easy.
Sorry for my bad english.
Im just pondering best practice with an application I'm developing. Its a simple one window application using qt creator. It's just going to start a QProcess and show the output in a QTextEdit box. To do this there needs to be a bit of processing between the output of the QProcess and the QTextEdit but i dont know where i should do this, should i create a new class to do that or add member functions and extra signals and slots to my main window? I dont want mainwindow to become bloated and hard to read but equally i dont want to have more source files than really I need.
Any thoughts?
The main window class can very easily get bloated with all kinds of functionality. I've dealt with that myself, so it's a very real trouble.
Really, though, this is not so much of QT question as it is an object-oriented design question. The key is that your output window does not need to be a part of QMainWindow, so it probably shouldn't be. Make the display a widget, and insert it onto the main window. That is much more flexible, as if you ever need to move that output pane for any reason, it won't be coupled to a specific part of the program.
The logic that feeds data into that output pane should also get its own class, separating the responsibility for displaying the output from the responsibility for acquiring the output.
For reference on the concepts behind my suggestion, see the Single Responsibility Principle and the separation of concerns.
Also - you may wish to have a read at this link to model view delegate information which is how I tend to develop in Qt. Like the person above says - this is more a question of good OO design.
Currently, I am in the design phase of a Qt widget like what one would see in a typical hex editor. It seemed simple enough to begin with, but as I dig into its implementation details I’m having some confusion.
Basically, the widget would consist of 3 core components: It will inherit QAbstractScrollArea or QScrollArea to provide scrolling and, in the viewport margin, it will display the file offset of each line. Then there will be two text editors; one with the hexadecimal value of each byte of the file, and one with the plaintext character representation.
I, of course, first checked qt-apps.org for any existing widgets, but a search for “hex” only returned QHexEdit and qPHexEditor, neither of which are very complete. I then considered creating a widget completely from scratch as they had, but felt like there should be a more elegant solution. Qt already has much text-editor functionality built into QTextEdit and QPlainTextEdit; why reinvent the wheel?
Now, while the “plaintext view” would be as simple as using a QPlainTextEdit with a fixed-width font and a width of 16 characters, the “hex view” is giving me a headache. I’ve been poring over QTextEdit, QAbstractTextDocumentLayout, etc., trying to figure out a way to present the desired appearance. For those who have never used a hex editor, it should function like so: – Using a fixed-width font, widget should be the width of 47 characters – Widget should display 2 hexadecimal characters per byte, with a blank space between bytes—-16 bytes per line
Since that thought, I’ve been trying to figure out how to subclass any related classes to provide the desired formatting. Unfortunately, the text editing classes don’t seem to follow the model/view framework as closely as I’d hoped, so deriving a new “view” for it doesn’t seem easy. Ideally, the widget would function like so:
One document/model for both the “hex” and “plaintext” views. Editing either view would adjust this model and update the other view appropriately. Signals/Slots at its best.
Because QTextEdit and QPlainTextEdit already provide much of the functionality needed (visible cursor, selections, undo/redo, native look and feel, etc), it would be ideal to re-use this.
So, does anyone have any recommendations? I appreciate any input on this.
QHexEdit2 is a quite complete editor widget for binary data. It can edit very big files, is available for Qt4, Qt5, PyQt4, PyQt4 with python 2 and 3.
see https://github.com/Simsys/qhexedit2
I'm new to QT, and am trying to figure out the best means of creating a WYSIWYG editor widget for a custom markup language that displays simple text, images, and links. I need to be able to propagate changes from the WYSIWYG editor to the custom markup representation.
As a concrete example of the problem domain, imagine that the custom markup might have a "player" tag which contains a player name and a team name. The markup could look like this:
Last week, <player id="1234"><name>Aaron Rodgers</name><team>Packers</team></player> threw a pass.
This text would display in the editor as:
Last week, Aaron Rodgers of the Packers threw a pass.
The player name and the team name would be editable directly within the editor in standard WYSIWYG fashion, so that my users do not have to learn any markup. Also, when the player name is moused-over, a details pop-up will appear about that player, and similarly for the team.
With that long introduction, I'm trying to figure out where to start with QT. It seems that the most logical option would be the Rich Text API using a QTextDocument. This approach seems less than ideal given the limitations of a QTextDocument:
I can't figure out how to capture navigation events from clicking on links.
Following links on click seems to only be enabled when the QTextEdit is readonly.
Custom objects that implement QTextObjectInterface are ignored in copy-and-paste operations
Any HTML-based markup that is passed to it as Rich Text is retranslated into a series of span tags and lots of other junk, making it extremely difficult to propagate changes from the editor back to the original custom markup.
A second option appears to be QWebKit, which allows for live editing of HTML5 markup, so I could specify a two-way translation between the custom markup and HTML5. I'm not clear on how one would propagate changes from the editor back to the original markup in real-time without re-translating the entire document on every text change. The QWebKit solutions looks like awfully bulky to me (Learning WebKit along with QT) to what should be a relatively simple problem.
I have also considered implementing the WYSIWYG with a custom class using native QT containers, labels, images, and other widgets manually. This seems like the most flexible approach, and the one most likely not to run into unresolvable problems. However, I'm pretty sure that implementing all the details of a normal text editor (selecting text, font changes, cut-and-paste support, undo/redo, dragging of objects, cursor placement, etc.) will be incredibly time consuming.
So, finally, my question: are there any QT gurus out there with some advice on where to start with this sort of project?
BTW, I am using QT because the application is a desktop application that needs platform independence.
Given that I got no advice here, I decided to go with the QTextEdit approach, although I'm actually using a QTextBrowser that is set to be editable so that I can capture link navigation events. I will be using QTextCharFormat's with the link names set to unique identifiers in order to convert from the QTextEdit back to the custom markup. The QTextEdit supports images already, so I won't have to deal with those.
I think I will hit the biggest roadblocks with the fact that I need to be able to insert/grow/shrink tables whose cells can have Excel-style functionality. I have not yet figured that whole process out.
I have a Flex application, which loads a SWF from CS3. The loaded SWF contains a text input called "myText". I can see this in the SWFLoader.content with no problems, but I don't know what type I should be treating it as in my Flex App. I thought the flex docs covered this but I can only find how to interact with another Flex SWF.
The Flex debugger tells me it is of type fl.controls.TextInput, which makes sense. But FlexBuilder doesn't seem to know this class. While Flash and Flex both use AS3, Flex has a whole new library of GUI classes. I thought it also had all the Flash classes, but I can't get it to know of ANY fl.*** packages.
The fl.* hierarchy of classes is Flash CS3-only. It's the Flash Components 3 library (I believe it's called, I might be wrong). However, you don't need the class to work with the object. As long as you can get a reference to it in your code, which you seem to have, you can assign the reference to an untyped variable and work with it anyway:
var textInput : * = getTheTextInput(); // insert your own method here
textInput.text = "Lorem ipsum dolor sit amet";
textInput.setSelection(4, 15);
There is no need to know the type of an object in order to interact with it. Of course you lose type checking at compile time, but that's really not much of an issue, you just have to be extra careful.
If you really, really want to reference the object as its real type, the class in question is located in
Adobe Flash CS3/Configuration/Component Source/ActionScript 3.0/User Interface/fl/controls/TextInput.as
...if you have Flash CS3 installed, because it only ships with that application.
Flex and Flash SWFs are essentially the same, just built using different tools. I'm not sure if they share the same component libraries, but based on the package names I'm guessing they at least mostly do.
If it's a normal Text Input then I would guess it's an instance of mx.controls.TextInput.
Keep in mind that if you do as Theo said and reference it with the correct type it will compile that class in both swfs, even if you're not using it in the first one. Unfortunately the fl.* classes don't implement any interfaces so you can't type them to the interface instead of the implementation. If you could, only the interface would get compiled, which is much smaller than the implementation. For this one it won't be a big deal, it's probably going to add only a couple kb, but in the long run it adds up. Just a heads up ;)