Custom decoration for QListView - c++

I'm writing a GUI that runs on both Linux and Windows, and makes extensive use of the QListView class. I'd like to keep the look of the GUI consistent for users on both systems.
Out of the box, Qt uses different decorations for expandable/collapsible item icons on those systems. Is there any way, perhaps using a delegate, to replace the decoration with a custom set of icons?

If you are using Qt 5.* you can use the platform independent Fusion style. It looks pretty much the same on different platforms. Just add in your main.cpp :
qApp->setStyle("fusion");

Related

How to put system icons in menus?

I have run the menu example from Qt and there are no icons on menus, only text. Most apps (like pcmanfm and caja from Ubuntu) have similar icons, so I suppose they are system-wide and not application specific. How could I put icons in menu items? A code sample would be interesting.
To obtain the icons of the systems you must use the method QIcon::fromTheme()
Example:
newAct = new QAction(tr("&New"), this);
newAct->setIcon(QIcon::fromTheme("document-new"));
Qt uses as a backend to freedesktop icon, it has a rule in the names, the updated list of them can be found in the following link
The QIcon::fromTheme() function found in the other answer is unfortunately not portable to Mac or windows. You may have better luck using QStyle::standardIcon().

How to create an Evernote kind of widget for global menu of a MacOS/X desktop using QT?

How to create an application which stays in top of MacOS, something similar to below image. You can see the Evernote elephant icon.
I don't want to use xcode - because my application already built in QT, it has nice GUI, now I wanted to add extended feature something similar to Evernote. If I click on an elephant it will open a dialog box to write notes. In my case- it's a simple event like on/off buttons.
I have tried and created GUI widget apps but how to make one which resides like Evernote app ?
A custom pop up menu like the one pictured can be done several ways in Qt.
QML is the most modern way of making the menu with the customized styling you are looking for.
Apply the appropriate flags to the window/widget so it appears as a popup.
The same effects can also be done in QWidgets, but takes more code and probably will take longer to make. The flags you are looking for will be found under Qt Window Flags and/or under Qt Widget Attributes.
The stock stylings for Qt for different OS's deal mostly with title bars, status bars, buttons, drop downs, etc.
The base styles for Mac can be found here:
http://doc.qt.io/qt-5/gallery-macintosh.html
Once you go to a customized popup, you have to draw all of it yourself... but the native drawing elements in Qt are friendly enough and get you that look you are trying to do.
There are even some tools for exporting from Photoshop or Gimp directly to QML.
http://doc.qt.io/qtcreator/quick-export-to-qml.html
Hope that helps.
You are looking for a tray icon. Qt implements it in QSystemTrayIcon.
Further information
You may take a look at the System Tray Icon Example.
Many StackOverflow posts exist on this topic.
If you already have a program written for Qt, then you can compile and run it under MacOS/X much the same way you could compile it under (whatever OS you're using now). You'll need to install Xcode because Xcode includes the C++ compiler (clang) you'll need in order to compile your Qt program, but you don't have to use the Xcode IDE if you don't want to. Rather, you can either use the QtCreator IDE under MacOS/X, or you can simply open up a Terminal window and do a "qmake ; make" in the directory where your Qt-based program's .pro file is, and build it from the command line that way.
If, on the other hand, your question is actually about how to add an icon to the global menu of a MacOS/X desktop, then I don't think Qt has an API for that, so you'll need to drop down to using one of MacOS/X's native APIs. That will probably involve learning some Objective-C (or Objective-C++, if you prefer), but integrating a bit of Objective-C/C++ into your Qt app is doable with a bit of work.

QT How to embed an application into QT widget

In our project we have three independent applications, and we have to develop a QT control application that controls these three applications. The main window will be seperated to three sub windows - each one display another one application.
I thought to use QX11EmbedWidget and QX11EmbedContainer widgets, but two problems with that:
The QX11Embed* is based on X11 protocol and I dont know if it's supported on non-x11 systems like Windows OS.
Since QT 5 these classes are not existing, and the QT documentation doesn't mention why.
So that I dont know whether to use it or not - I'll be happy to get an answers.
In addition, I see that the QT 5.1 contains QWidget::createWindowContainer(); function that in some posts it looks like this should be the replacement to the X11Embed. Can anyone please explian me more how can I use this function to create a QT widget that will run another application (a Calculator for example) inside its?
I have searched a lot in Google, and didn't find answers to my Qs.
Can anyone please help me? Am I on the right way?
Thanks!
If all three independent applications are written with Qt, and you have their source, you should be able to unify them just through the parenting of GUI objects in Qt.
http://qt-project.org/doc/qt-4.8/objecttrees.html
http://qt-project.org/doc/qt-4.8/widgets-and-layouts.html
http://qt-project.org/doc/qt-4.8/mainwindows-mdi.html
If you don't have access to them in that way, what you are talking about is like 3rd party window management. It is kind of like writing a shell, like Windows Explorer, that manipulates the state and the size of other window applications.
Use a program like Spy++ or AutoIt Spy for Windows and the similar ones for other OS's, and learn the identifying markings of your windows you want to control, like the class, the window title, etc. Or you can launch the exe yourself in a QProcess::startDetached() sort of thing.
http://qt-project.org/doc/qt-5.1/qtcore/qprocess.html#startDetached
Then using the OS dependent calls control the windows. The Qt library doesn't have this stuff built in for third party windows, only for ones under the QApplication that you launched. There are a lot of examples of doing things like this by AutoHotKey, or AHK. It is a scripting language that is made for automating a lot of things in the windows environment, and there is port for Mac as well (though I haven't tried the mac port myself).
So in the end you are looking at finding your window probably with a call like this:
#include <windows.h>
HWND hwnd_1 = ::FindWindow("Window_Class", "Window Name");
LONG retVal = GetWindowLongA(hwnd_1, GWL_STYLE); // to query the state of the window
Then manipulate the position and state of the window like so:
::MoveWindow(hwnd_1, x, y, width, height, TRUE);
::ShowWindow(hwnd_1, SW_SHOWMAXIMIZED);
You can even draw widgets on top of the windows you are controlling if you set your window flags correctly for the windows you are manipulating.
transparent QLabel with a pixmap
Cannot get QSystemTrayIcon to work correctly with activation reason
Some gotchas that come up in Windows when doing all of this, is finding out the quirks of the Windows UI when they set the Display scaling different from what you expect, and if you want to play nice with the Task bar, and handling all the modal windows of your programs you are manipulating.
So overall, it is do-able. Qt will make a nice interface for performing these commands, but in the end you are looking at a lot of work and debugging to get it in a beautiful, reliable, window manager.
Hope that helps.
I never tried it myself, but from the docs in Qt 5.1 I would try QWindow::fromId(WId id), which gives you a QWindow, which should be embeddable with createWindowContainer:
QWindow * QWindow::fromWinId(WId id) [static] Creates a local
representation of a window created by another process or by using
native libraries below Qt.
Given the handle id to a native window, this method creates a QWindow
object which can be used to represent the window when invoking methods
like setParent() and setTransientParent(). This can be used, on
platforms which support it, to embed a window inside a container or to
make a window stick on top of a window created by another process.
But no guarantee. :-)

Qt and native menus

Does Qt support interaction with the native menu bar of an arbitrary window (i. e. QWidget) on Windows and Linux?
It looks like Qt treats the menu as just another child widget to be placed on the parent window. That is, to have a menu bar , I must reserve some space for it in the window's client area. That makes no sense on Mac, with its menu on the top of the screen. On Windows, it makes little sense - the menu, as implemented by the system, is outside of the client area. Not sure what's the native model on Linux.
Qt supports native menues on Mac and on Windows. It may seem when looking at the forms in Qt Designer, that Qt menues on Mac are non-standard, but they aren't. Qt had made a great deal to deal with menue differences between the supported platforms and they work very well.

Custom Windows GUI library

I always wondered how software such as iTunes, Winamp etc is able to create its own UI.
How is this accomplished under the Windows platform? Is there any code on the web explaining how one would create their own custom GUI?
WinAmp doesn't usually supply its own GUI at all -- it delegates that to a "skin". You can download dozens of examples and unless memory fails me particularly badly, documentation is pretty easily available as well.
From the looks of things, I'd guess iTunes uses some sort of translation layer to let what's basically written as a native Mac UI run on Windows (the same kind of thing that Apple recently decided was so evil that they're now forbidden on the iPhone and apparently the iPad).
Since saying anything that could possibly be construed as negative about Apple is often treated as heresy, I'll point to all the .xib files that are included with iTunes for Windows. An .XIB file (at least normally) is produced by Apple's Interface Builder to hold resources for OS/X programs, and compiled to a .NIB file prior to deployment. Windows doesn't normally use either .XIB or .NIB files at all, and it appears likely to me that Apple includes a compatibility layer to use them on Windows (though I've never spent any time looking to figure out what file it's stored in or anything like that).
Edit: (response to Mattias's latest comment). Rendering it is tedious but fairly straightforward. You basically take the input from the skin (for example) and create an owner draw control (e.g. a button) and render the button based on that input.
The easiest way to do this is to have fixed positions for your controls, and require the user to draw/include bitmaps for the background and controls. In this case, you just load the background bitmap and display it covering the entire client area of your application (and you'll probably use a borderless window, so that's all that shows). You'll specify all your controls as owner-drawn, and for each you'll load their bitmap and blit it to the screen for that control. Since there won't (usually) be a visible title bar, you'll often need to handle WM_NCHITTEST (or equivalent on other systems) to let the user drag the window around.
If you want to get a bit more complex, you can add things like allowing them to also specify a size and position for each control, as well as possibly specifying that some controls won't show up at all. Again, this isn't really terribly difficult to manage -- under Windows, for example, most controls are windows, and you can specify a size and position when you create a window. If the user loads a different skin at run-time, you can call MoveWindow to move/resize each control as needed.
I'm assuming that you mean creating a GUI application as opposed to a GUI framework.
There are lots of GUI frameworks available for Windows.
Some are
wxWidgets (www.wxwidgets.org)
Qt (http://qt.nokia.com/products)
And of course the venerable MFC framework (http://msdn.microsoft.com/en-us/library/d06h2x6e%28VS.90%29.aspx)
If you want a more complete list, look at the Wikipedia article for MFC (http://msdn.microsoft.com/en-us/library/d06h2x6e%28VS.90%29.aspx) and scroll to the bottom.
Each of these GUI frameworks is amply documented on the web.