I just started to work with delphi touch gestures. Because I have never done anything with multitouch, I want to first create a small image viewer with move/zoom/rotate functionality.
I have placed a TImage on a TScrollBox. Actually, when the onGesture method of the image is called, EventInfo is read to decided which gesture was recognized to show it in a message box. Like that, all of the gestures can be recognized but the pan gesture. I think this one is needed to move a picture when it's zoomed in by tapping and moving it. What am I doing wrong?
And is there a useful framework with built-in zoom/rotate functionality maybe?
The scrollbars already take care of panning.
Related
We need to overlay a target window with a custom shape and tracks the position of the target window such that the overlay drawing always appears above it. Also, the overlay drawing should appear in screenshots taken using BitBlt or PrintClient by screen-capturing tools like Camtasia, Debut, etc. Also, moving the target window around should not leave traces of the drawing at earlier location. The target window is not made using our code.
So far we've tried several ways but each method has its problems:
1) Layered Window:
Using a layered window as the child/owned window of the target window is the easiest thing and it works. But the problem is on Windows 7 and XP, layered windows do not appear in a BitBlt done without the CAPTUREBLT flag and the screen-capturing tools may call BitBlt without the flag, thereby skipping our window from the capture.
2) Region Window:
The crude approach to support all Windows versions then is to use a region window using SetWindowRgn and make the target window its owner. However, region windows are generally very slow in rendering complex shapes and also impact the performance of other windows, sometimes to the point of freezing the application. Region window also leaves traces on dragging the application window.
3) Subclassing and Drawing on HDC:
Another approach is to sub-class the target window and draw the shape on its HDC on the OnPaint() event inside the window procedure hook. The shape can be drawn on the desktop window instead too. The problem is that applications may draw without a paint event, like when some text is selected using the cursor, and such drawing may erase a part of the custom drawing. Tracking all possible paint events is not a good way to do this.
4) Drawing continuously in a timer:
The last resort is to draw the custom shape on the target window in a timer continuously so the drawing is always above the target, even on text selection. But this may show a bit of flicker when the text is selected. Not to mention, it is very performance heavy to draw constantly.
Question
What is the best way to achieve an overlay drawing which works on all Windows versions (since XP) at the same time appearing in screen-captures. We've exhausted all approaches. Is there some method I'm missing? Can the above mentioned ways be used with some improvement? Is DirectX an option? I'm looking for methods with fast rendering capacity to achieve this. Appreciate any help!
I think the best solution to draw an overlay window, is to use a double-buffered technique GDI, just like in this example:
Overlay Drawing in CScrollView
I have myself the same task, and the only solution was that one. Hope it help you.
For I have a javascript version GMap.html, I can successfully display it in the WP7 WebBrowser, but I cannot make it pan or zoom in; is there a way to disable the default gesture behavior(such as fix the position the map's div; if I slide up, the map pans to north, when I double touch, it zooms) to allow the GMaps panning or zooming?
Here attached a very simple sample, when opening the emulator, you can see the map is displayed, but when we want slide up/down to pan north or south, it works like panning the web browser up or down.
http://hotfile.com/dl/135072503/ec55e86/PhoneApp1.7z.html
Thanks,
You should be able to hook the manipulation events from the Border that surrounds the ContentPresenter in the visual tree for the WebBrowser control to intercept them before they get to the PanZoomContainer, which would allow you to do whatever you need to with the content.
Colin Eberhardt has a great post about it on his blog where he basically disabled the standard manipulation events for doing HTML5 apps on Windows Phone, but the concept is still the same.
with windows phone 7 i am using teh bing map control. i have it working just fine. however, the zoom buttons (+,-) are at the bottom of the page and difficult to see.
The buttons have black border with black text. They are easy to see on a light map background, but with black background they are in essence hidden.
Does anyone have an idea on how to make them easier to see?
As invalidusername said you can use the pinching to zoom in and out and it is probably a better way to do it. But in my case I haven't a device or touch screen so needed to use buttons in this way to test my map.
Rather than using the built-in zoom buttons I looked at the sample code from this tutorial which has icons for zoom in/out and data bound them to the zooming of the map. Adapting it to my needs. It works pretty well:
http://msdn.microsoft.com/en-us/wp7trainingcourse_usingbingmapslab_topic2
You can change the positioning/images etc.
As per DanielBallinger's comment the link above seems to no longer work. The following does:
Bing Maps Tutorial
The context menu from dock items is not only translucent but also blurs the contents behind it, Is this effect availible for translucent floating panels? This is the same effect used in Sheet Alert dialogs (e.g. quit with unsaved changes) but in that case the transparency is different, and the background is light rather than dark
Some background, we have a pro app that is frequently used full screen, and our floating palettes have some transparency, but obviously the more transparency we have the harder it is to read the text on them when the background is very active/noisy, if we could have a slight blur we would be able to greatly improve the readability on the text while still allowing some context of "whats behind the palette"
I think this is what you want: Using Core Image Filters On/Under a NSWindow
Beware that this is private API though, so if you're developing for the Mac App Store, this would be a problem.
A coworker is encountering an error when he tries to run a VB6 app we're working on. The error is, "480: Can't create AutoRedraw image". Microsoft's documentation says this is because "There isn't enough available memory for the AutoRedraw property to be set to True. Set the AutoRedraw property to False and perform your own redraw in the Paint event procedure or make the PictureBox control or Form object smaller..."
Making the PictureBox smaller isn't an option. I'd be glad to "...perform my own redraw in the Paint event procedure...", but I'm not sure how to go about it. Can someone show me the way?
Without details this will be a simplistic answer. In general most beginning VB6 programmers use AutoRedraw=True draw in responds to some input. Fill out some data, click draw, and it appears in the picture box.
The click event in the Draw Button is linked do your drawing code. The first step is move the call to the drawing code to the paint event of the picture. The second step is to replace all calls to the drawing code with MyPictureBox.Refresh. Refresh forces the paint event of that picture box to fire.
The main problem you will have to be concerned with is that the paint event is going to be fired everytime the form needs refreshed. Like if a window covering it is moved. This means that any speed issue in your drawing code will be exposed. AutoRedraw=True takes what you drew and puts in a hidden bitmap that the PictureBox uses to display what you drew.
The Paint event will execute each step of your drawing process so you have to make sure you are as fast as possible. Depending on how dynamic your application is the worse slowdown issues will become. If you are displaying a static image then the problem isn't as bad.
Making the PictureBox smaller isn't an option. I'd be glad to "...perform my own redraw in the Paint event procedure...", but I'm not sure how to go about it. Can someone show me the way?
That is easy. You just implement the _Paint()-Event of your Form or PictureBox and draw.
Because you are asking, i think i should clarify what the AutoRedraw-Propeprty does. If it is set to true, you can "just draw your image" any way you want. In multiple steps. Whatever. If it needs to be redrawn, for example, because another windows was on top it, it will be magically done. The down site is, that is slow, for the drawing part.
If AutoRedraw is false, no magic will happen. The Paint()-Event will be fired and you are responsible to draw your image again. This will be much faster, if your window is not "invalidated" (e.g. "covered") often. Or you are doing a lot of drawing.
Or you are running out of memory for the "magic space" ;-)
If you don't mind rewriting your graphics code to use the GDI API - this could be a fairly big task - I found this thread from 2006 in the VB6 discussion group, where Mike Sutton said in answer to a similar problem:
VB's back-buffer implementation uses a
Device Dependant Bitmap (DDB) to store
the image data, which is quite limited
in how large it can be made. On older
OS' this used to be ~16mb uncompressed
data size, on later OS this has been
expanded but is still quite
restrictive.
A workaround for this is to use a
Device Independent Bitmap (DIB) and
manage the GDI resources yourself,
have a look at the DIB article on my
site for an example of how to work
with them.
I haven't tried it myself.
There's usually a drop-down box of events for your control in the forms code window. You need to pick the paint event:
Private Sub object_Paint()
and fill in your your code for drawing on the PictureBox.