to get QWidgetImage to a point where it can fill a need we have: to be
able to use Qt to make HUDs and to display widgets over / inside an OSG
scene.
---------------
Current results
---------------
I've attached what I have at this point. The modified QWidgetImage +
QGraphicsViewAdapter classes can be rendered fullscreen (i.e. the Qt
QGraphicsView's size follows the size of the OSG window) or on a quad in
the scene as before. It will let events go through to OSG if no widget
is under the mouse when they happen (useful when used as a HUD with
transparent parts - a click-focus scheme could be added later too). It
also supercedes Martin Scheffler's submission because it adds a
getter/setter for the QGraphicsViewAdapter's background color (and the
user can set their widget to be transparent using
widget->setAttribute(Qt::WA_TranslucentBackground) themselves).
The included osgQtBrowser example has been modified to serve as a test
bed for these changes. It has lots more command line arguments than
before, some of which can be removed eventually (once things are
tested). Note that it may be interesting to change its name or split it
into two examples. Though if things go well, the specific QWebViewImage
class can be removed completely and we can consolidate to using
QWidgetImage everywhere, and then a single example to demonstrate it
would make more sense, albeit not named osgQtBrowser... You can try this
path by using the --useWidgetImage --useBrowser command line arguments -
this results in an equivalent setup to QWebViewImage, but using
QWidgetImage, and doesn't work completely yet for some unknown reason,
see below.
----------------
Remaining issues
----------------
There are a few issues left to fix, and for these I request the
community's assistance. They are not blockers for me, and with my
limited Qt experience I don't feel like I'm getting any closer to fixing
them, so if someone else could pitch in and see what they can find, it
would be appreciated. It would be really nice to get them fixed, that
way we'd really have a first-class integration of Qt widgets in an OSG
scene. The issues are noted in the osgQtBrowser.cpp source file, but
here they are too:
-------------------------------------------------------------------
QWidgetImage still has some issues, some examples are:
1. Editing in the QTextEdit doesn't work. Also when started with
--useBrowser, editing in the search field on YouTube doesn't
work. But that same search field when using QWebViewImage
works... And editing in the text field in the pop-up getInteger
dialog works too. All these cases use QGraphicsViewAdapter
under the hood, so why do some work and others don't?
a) osgQtBrowser --useWidgetImage [--fullscreen] (optional)
b) Try to click in the QTextEdit and type, or to select text
and drag-and-drop it somewhere else in the QTextEdit. These
don't work.
c) osgQtBrowser --useWidgetImage --sanityCheck
d) Try the operations in b), they all work.
e) osgQtBrowser --useWidgetImage --useBrowser [--fullscreen]
f) Try to click in the search field and type, it doesn't work.
g) osgQtBrowser
h) Try the operation in f), it works.
2. Operations on floating windows (--numFloatingWindows 1 or more).
Moving by dragging the titlebar, clicking the close button,
resizing them, none of these work. I wonder if it's because the
OS manages those functions (they're functions of the window
decorations) so we need to do something special for that? But
in --sanityCheck mode they work.
a) osgQtBrowser --useWidgetImage --numFloatingWindows 1
[--fullscreen]
b) Try to drag the floating window, click the close button, or
drag its sides to resize it. None of these work.
c) osgQtBrowser --useWidgetImage --numFloatingWindows 1
--sanityCheck
d) Try the operations in b), all they work.
e) osgQtBrowser --useWidgetImage [--fullscreen]
f) Click the button so that the getInteger() dialog is
displayed, then try to move that dialog or close it with the
close button, these don't work.
g) osgQtBrowser --useWidgetImage --sanityCheck
h) Try the operation in f), it works.
3. (Minor) The QGraphicsView's scrollbars don't appear when
using QWidgetImage or QWebViewImage. QGraphicsView is a
QAbstractScrollArea and it should display scrollbars as soon as
the scene is too large to fit the view.
a) osgQtBrowser --useWidgetImage --fullscreen
b) Resize the OSG window so it's smaller than the QTextEdit.
Scrollbars should appear but don't.
c) osgQtBrowser --useWidgetImage --sanityCheck
d) Try the operation in b), scrollbars appear. Even if you have
floating windows (by clicking the button or by adding
--numFloatingWindows 1) and move them outside the view,
scrollbars appear too. You can't test that case in OSG for
now because of problem 2 above, but that's pretty cool.
4. (Minor) In sanity check mode, the widget added to the
QGraphicsView is centered. With QGraphicsViewAdapter, it is not.
a) osgQtBrowser --useWidgetImage [--fullscreen]
b) The QTextEdit and button are not in the center of the image
generated by the QGraphicsViewAdapter.
c) osgQtBrowser --useWidgetImage --sanityCheck
d) The QTextEdit and button are in the center of the
QGraphicsView.
-------------------------------------------------------------------
As you can see I've put specific repro steps there too, so it's clear
what I mean by a given problem. The --sanityCheck mode is useful to see
what should happen in a "normal" Qt app that demonstrates the same
situation, so hopefully we can get to a point where it behaves the same
with --sanityCheck and without."
I've needed to run a recorded simulation offscreen and save it to a sequence of images, and the ScreenCaptureHandler seemed to be the simplest way to do that, and with this change it's possible.
Another change: I've also added the ability to specify continuous capture of all frames, or a certain number of frames. ScreenCaptureHandler now has a setFramesToCapture(int) method. The argument will be interpreted as:
0 : don't capture
<0 : capture continuously
>0 : capture that number of frames then stop
I also added startCapture() and stopCapture() methods so that user code can start capturing (either continuously or the given number of frames) at a given point in their program. setFramesToCapture() won't start capturing, you have to call startCapture() afterwards. The handler also now has another key to toggle continuous capture (defaults to 'C').
Note that continuous capture will of course only work if the CaptureOperation writes to different files (for example, a WriteToFile with SEQUENTIAL_NUMBER mode) or does something different each time... Otherwise it will just overwrite of course. :-)
I've also taken the chance to refactor the addCallbackToViewer() method a bit too, since finding the right camera is needed in two places now.
I've tested all cases (I think). If you want to try, in osgviewer.cpp and replace the line
// add the screen capture handler
viewer.addEventHandler(new osgViewer::ScreenCaptureHandler);
with
// add the screen capture handler
osgViewer::ScreenCaptureHandler* captureHandler = new
osgViewer::ScreenCaptureHandler(
new osgViewer::ScreenCaptureHandler::WriteToFile(
"screenshot", "jpg",
osgViewer::ScreenCaptureHandler::WriteToFile::SEQUENTIAL_NUMBER),
-1);
viewer.addEventHandler(captureHandler);
captureHandler->startCapture();
And vary the "-1" (put 0, 10, 50) and then use the 'c' and 'C' keys and see how it reacts.
"
It's a minimal change, it just calls an already existing protected method. It was trivial to subclass the handler to do it in our code, but pushing the change into OSG makes sense as it's generally useful to have it in the handler itself.
I also noticed that the handle() method was overridden from osgGA::GUIEventHandler but wasn't marked virtual. It wasn't intended that subclasses not be able to override it in turn, so I've added the keyword.""
facilitate the subclassing of Image providing interactive behaviours so as
used in the vnc interactive VncImage class.
osgViewer::InteractiveImageHandler provides an event handler that convertes osgGA
mouse and keyboard events into the coordinate frame of an image based on ray intersection with geometry in
the associated subgraph.
Changed the ordering of events processing in Viewer and CompositeViewer to allow
scene graph event handlers to take precidence over viewer event handlers and camera manipulators
This code will add two extra statistics options:
-Camera scene statistics, stats for the scene after culling (updated at 10 Hz)
-View scene statistics, stats for the complete scene (updated at 5 Hz)
Each camera and each view will expand the statistics to the right.
I also added the requests and objects to compile of the databasepager to the databasepager statistics.""
viewer.addEventHandler(new osgViewer::ScreenCaptureHandler(
new osgViewer::WriteToFileCaptureOperation("filename", "jpg")));
and the filename will be what you want. The WriteToFileCaptureOperation will add the context ID and the file number (if in SEQUENTIAL_NUMBER mode) to the file name.
(The attached also clarifies some notify messages, and corrects the comment when adding the handler in osgviewer.cpp)
I also remembered, the current architecture could allow a different CaptureOperation for each context, but currently the API only allows setting one CaptureOperation for all contexts. This could be improved if need be.
"
