I would like to add several QGraphicsItem objects to a scene and have them all be transparent (i.e. visible but not completely opaque) with respect to another QPixmapItem background image which is also part of the scene yet obscure each other.
At the moment I am not sure whether this is possible it all. Making all objects in question children of some other QGraphicsItem and then making the parent transparent does not have the desired effect so I guess I'm looking for some completely different approach but I have no idea where to start on this.
EDIT: It seems my explanation was not quite clear enough, I will try to add an example in a few hours time.
From what I understood, you wish to have QGraphicItems which have an opacity less than 100% so that the background image is visible.
To achieve the same, you can use the set opacity function.
I'd like to create a context menu looking similar to this one:
I read suggestions on the web that QWidget::setMask() should be used to create a shape. But how can it fit the variable number of items then? Moreover, the same menu item may take more or less screen space on different machines.
Another question is how to create a shadow around this custom shape? As far as I understand, the mask allows to crop the widget, but not to make it semi-transparent.
I don’t found an easy way to do that! But here goes a way!
Instead of using the Qt mask API, I've used a frame-less widget with transparency enabled!
To draw the shadow, I've used radial gradient!
You can change the size of the menu before opening it, however you can’t resize it after opened (for example resize with mouse).
It’s quite easy add or remove widgets, just respect the layout margin to not draw outside the bounds destined to widgets. To simplify your life I created an inherited class of QPushButton with colors you can easily customize with style sheet.
See the result:
You can browse the source
Hope that helps!
I have a problem with redrawing in flex 4. I have a spark titleWindow, and if i drag it faster, it looks like it's mask is one frame late after the component.
it's easily visible with 1pixel thin border, because it becomes invisible even with slower movement.
You can try it here (what is not my page, but it's easier to show you here than uploading example):
http://flexponential.com/2010/01/10/resizable-titlewindow-in-flex-4/
If you move in direction up, you see disappearing top border. in another directions it's not that sensitive as it has wide shadow, and it's not very visible on shadow.
On my computer i see it on every spark TitleWindow i have found on google, although it's much less visible with less contrast skins, without borders or with shadows.
Do you see it there? i had never this problem with halo components. It's doing the same thing with different skins. I tried to delete masks from skin, cache component, skin even an application as bitmap with no success.
I also turned on redraw regions in flash player, and it looks like it's one frame late after titlewindow too.
Does anyone know why is it doing this or how can i prevent it?
Thank you
UPDATE:
no answers? really?
I have been facing the same problem and I was really pissed that I couldn't find any answer.
The problem with me was, that I tried to center the component "component.x = (parent.width - component.width) / 2" and then draw that component programatically. The problem was, that component.x is a Number which can lead to floating values like 10.5 or similar. And it looks like that bitmapFill function rounds floats DIFFERENTLY than drawRect function, which makes exactly the 1px line around the objects (but ONLY when parent.width is an odd number). Strange thing for me was, that I only called the Draw function once, but still this line keep recurring ...
Doing Math.floor(component.x) solved the issue.
P.S.: I think that you can also help your issue by setting cacheAsbitmap=true on the dragged object ...
Cheers,
Jan Prazma
I have a canvas which I want to accept drags on.
I have added a dragOver and dragEnter event listeners to the canvas, but they only work if I drag over something inside the canvas (another child element).
I realised that if I set the canvas' background colour to black it works. So I have set it's background transparency to 0, which works... buy is there a better way to work around this apparent need for the canvas to have something inside it to accept dragEvents.
Thanks
Rob
According to one of the Flex developers, "In Flash there is a difference between a transparent pixel and an area in a Sprite that hasn't been drawn on at all." (http://www.mail-archive.com/flexcoders#yahoogroups.com/msg127690.html)
I'm guessing this is the reason why you need to have the transparent background. For what it's worth, this is always the way I've seen this problem solved. There is also this question which talks about this problem.
Hope this helps!
I'm developing a Flex 2 application, and I noticed that part of the library which is responsible for moving GUI windows (TitleWindows) around when you drag them with the mouse gets confused if there is a clickable (buttonMode = true) sprite beneath them. When I say confused, I mean that the window is moved around normally for a while, but then at some point "jumps" into the upper left corner of the flash app, and makes very minor movement there. Then at some other point it jumps back. It is more difficult to explain than to experience, so please go and see for yourself. Here's how to reproduce the problem:
Go to http://www.panocast.com
In the left sidebar, choose "Real Estate"
Just below the bottom right corner of the flash window, choose "high res" by clicking on the rightmost icon.
When (part of) the video loads, click on the staircase. A TitleWindow will pop up.
Try dragging it around the screen. When the mouse cursor is moved above one of the clickable areas (like the staircase), the window is misplaced.
(Sorry, but can't give you a direct link, part of the page is generated dynamically.)
(What's makes the problem even more interesting is that for me, in "low res" mode, the problem does not occur! There is very little difference between the various modes.) I would really appreciate if someone told me what was going on here and how it can be fixed.
I'm not sure if it matters, but the underlying sprite is actually not just plain sprite, rather it is a Papervision3D renderer object with some 3D elements in it. I'm telling this because it is possible that the incorrect mouse coordinates somehow come from the texture UV mapped on the clickable objects.
I've managed to replicate this on the low res mode as well, so I don't think it's related to the resolution.
This looks to be because the MouseEvent is being handled by the TitleWindow AND the Papervision3D window. Perhaps you need to force stopImmediatePropagation() on one or the other? Or maybe switch off the MouseEvent handling for the Pv3D window when the TitleWindow pops up?
That's a tough one to debug without some source; something's apparently calling either move() or setting x and y properties on that TitleWindow and scheduling it be moved.
When I first read the post, it "smelled" like maybe a rotation miscalculation somewhere (using Math.atan vs. Math.atan2 can sometimes have that kind of effect), so you're right, it could have something to do with PaperVision, assuming you're not using Math.atan or setting rotation properties yourself anywhere. Just thought I'd mention it, though it's probably not happening in your case. You never know, though. ;)
More likely the LayoutManager is moving the component in response to a property change on the component. The Flex docs explain that in addition to setting its x and y properties, and explicit calls to move(), a UIComponent's move event can also be triggered when any of the following other properties change:
minWidth
minHeight
maxWidth
maxHeight
explicitWidth
explicitHeight
PaperVision or no, maybe that info might help you isolate the source of the move. Good luck.
I got this figured out. Apparently, this is a Papervision3D problem. There is a class deep inside Papervision3D called VirtualMouse, which is supposed to generate MouseEvents programmatically. This happens, for example, when the user interacts with any of the interactive objects on stage, e.g., a Plane with an interactive material on it (as in my case).
The problem is that the x and y coordinates of the generated event represent texture UV coordinates (just as I suspected) and not real world screen coordinates. When a TitleWindow (or any Panel object) is dragged, a "mouseMove" handler (among others) is added to the SystemManager, which then uses the stageX and stageY properties of the event object to determine the new position of the window. Unfortunately for VirtualMouse's mouse events, these are invalid, since the original x,y coordinates, which are probably used to determine the global stage coordinates are, as I said, not screen coordinates.
Honestly, I'm still unsure whether the events dispatched by VirtualMouse are used anywhere within Papervision3D itself, or they are just offered for convenience, but they sure make it difficult to integrate a viewport into a Flex program. Assuming that such events aren't necessary for PV3D itself, there is a one-liner fix for my problem, which must be added right after the creation of the viewport:
viewport.interactiveSceneManager.virtualMouse.
disableEvent(MouseEvent.MOUSE_MOVE);
BTW., there was a very similar (or rather, as it turns out, the same) bug with dragging sliders, also fixed by this line.