I know how to change the background on a single row in a TRichEdit control. But because this is applied to the selected text only, I can't set the background color of the whole line (client left to client right), only to the text part.
I tried to use the WM_ERASEBKGND message, but it doesn't work because a RichEdit control is painting the background in its WM_PAINT handler.
I also tried to set the brush to bsClear before calling the WM_PAINT handler, but it didn't work either.
Is it possible at all to have a custom drawn background?
You'll be able to do so by using the EM_SETBKGNDCOLOR message.
Related
I cannot find how to protect a drawing in a PictureBox control from being corrupted (wiped out) when I call a dialog to save the form or print it out. The form is saved or printed out OK, but the dialogs wipe out most of the PictureBox drawing after they leave. Yet the buttons and progress bar on the form are restored OK -- so there must be a way to 'protect' the PictureBox drawing as well. How is it done?
The reason is that you need to repaint the picture box after the dialog has gone away.
Your picture box will get a Paint event, that will tell you that you need to do some re-drawing.
In there, use the supplied graphics contexts etc to draw on the picture box again. Probably you will want to write a separate method that does drawing, and call it for an initial view, and also during that paint. But that's up to you.
If you will always have olny one picture in your PictureBox, or you will be always using pictures with of same size you can just override OnEraseBkgnd function for this control and return TRUE on exit of this function.
This way content of your will not be altered by unplanned OnPaint or OnEraseBkgnd calls.
I'm writing an OS X app (target 10.10, Xcode 6.1) and I'm really confused by my custom NSButtonCell subclass. It seems like there are things going on here that shouldn't. I'm new to OS X programming, so I'm asking if anyone has insight into the inner workings of NSButtonCell.
First, what seems to be working?
I can set the button's image and title. The image appears normally.
The storyboard sets up the button to be Style: Textured and Type: Momentary Change. It's not Bordered, not Transparent, and doesn't allow Mixed State.
List of complaints:
I override -drawTitle:withFrame:inView: to draw the title in a custom color depending on the cell's highlighted. This color should be #cccccc when the cell is not highlighted, but it's actually #d6d6d6.
The button has both image and alternate image. The image that's drawn is never the alternate image, so I override -drawImage:withFrame:inView: to pick the correct image for cell's highlighted. This appears to work, but what the heck, NSButtonCell? How is on/off state different from highlighted? I've tried many of the Type options and none seem to change the fact that pressing the button will momentarily change highlighted, and toggle state.
Speaking of momentarily changing highlighted, it appears that its duration is about as short as possible, so I had to implement a sort of "debouncer" to prevent -drawWithFrame:inView: from being called more frequently than a specified threshold.
My button cell also has properties myBackgroundColor and myAlternateBackgroundColor. I'm not using backgroundColor because I need to be able to draw a custom background shape (filled rect, filled circle, etc). The alternate background color is used when highlighted. The problem here is that the alternate background color should be #93edbf but appears to be #a1eecb! In order to get it to look like #93edbf, I need to set the color to #84ecb2.
So far this has all been about one particular instance of this button cell. But in another instance, the alternate background isn't drawing at all! I've read through the storyboard code and the buttons are as identical as they can be. My view controller code likewise updates both button cells' properties at the same time. Why would one button behave differently from another?
I want the button to highlight on mouse down instead of "momentarily" after mouse up. I haven't yet implemented this in my custom cell. Man, NSButtonCell is really lacking some things. How does something like that happen? Don't the OS X and iOS teams ever talk to each other?
What could it be?
I've already verified that the cell's controlTint is set to NSClearControlTint. I've checked for background filters, compositing filters and content filters on the off chance they had anything to do with this.
I know Apple really wants us to use their native look and feel for UI elements, but I never thought they'd go so far as to force the use of some highlight tint.
Maybe I am missing something, but is it the case that when you set a pictureboxes background to transparent, all it really does is set it to the same color as the forms background?
What I am trying to do is draw an animation for the benefit of this, a bouncing ball - which I paint on the form, then overlay that with a picture frame. End result should be a bouncing ball in a picture frame, I should mention that the picture frame does not have a straight edge, so it is not possible to arrange 4 picture boxes in a frame. The ball needs to vanish behind the frame to change color and then magically bounce back out.
I have tried:
1.Setting the picture box background to pink and then key out the same pink, this basically cuts away everything, including that which is behind the picture box
2.Setting the picture box to transparent, this just displays the picture box background as the same color as the forms background.
3.I have tried painting the image in a rectangle, this had the same effect as drawing it in a picture box.
I am not sure what I am doing wrong, I am wondering if there is any other ways I could try or if someone has made a custom control or library that supports transparency?
Try using a Panel with the background image set. This is because; as you said: the transparent option only takes the backcolour of the parent.
After doing some more in depth research I solved this by drawing both the images to the form using PaintEventArgs and me.paint
Making each image transparent using:
Dim TestImage as Bitmap
TestImage.MakeTransparent(<Transparency Color>)
Thank you to both of you for your replies though.
Hmm... If You want to use Picturebox and get a transparent image,
Try to set picturebox's background as your 'Ball' (probably you need an image editor).
and set picturebox transparent. It worked for me (VS Express 2010) once.
Is it possible to programatically set Petrel's Window3D's background color?
I saw that you can use the ISettingsInfo to get/set the color, but I am wanting to know how to make the window's background update.
Beginning in 2012.1 you can get (or set) the background color for a Window3D by querying for the appropriate IColorInfoFactory and getting the ColorInfo instance for the window in question. However, this only applies when the window is toggled to its non-black state.
The Petrel 3D Window's "Change background color" function toggles between black and the color specified in the window's Settings tab. Unfortunately, the ColorInfo API only exposes that color from the Settings tab, so as of 2012, there is no way to know whether the window is currently toggled to a black background or to the specified color.
In VisualBasic.Net When I activate a picture box and then draw something on it, it draws and then immediately goes blank. Works fine when I re-draw it, but almost always messes up the first time I draw on it. This has happenned with several different programs, and the help file is no help.
Try setting the DoubleBuffered property
http://msdn.microsoft.com/en-us/library/system.windows.forms.control.doublebuffered.aspx
If that's not it, please provide more info.
Usually, if you're drawing something on a picture box or on another control, you have to take over the OnPaint event, and you're responsible of persisting what you draw on this event.
Thank you Andrew, but no help. I'm using .Net Framework 1.1, which does not offer the DoubleBuffered property... it was new in 2.0.
Not sure what additional info to provide.. the code is 300 lines long. When a button is clicked, the code expands my form, makes two picture boxes visible (one on top of the other (the back one is for some graph labels), and then uses some graphic brushes and pens to draw a graph on the front box. There's some database activity and calculations going on in the background at the same time.
I assume you're using the standard PictureBox component. Do you draw in the Paint-Handler? If not then the PictureBox will just erase your painted stuff next time it's asked to redraw itself (erase background etc.).
Yes, I believe I am using the standard picture box.
By Paint-Handler, I assume you mean a [Control].PaintEvent Handler. No I'm not using an event handler to do the drawing... drawing my chart is not an event in itself, but part of a much larger response to a button click event.
If you are saying that having the drawing code be part of a separate and specific handler can solve my problem, than I guess I could raise an internal event every time I want to redraw the chart. But I Would rather just figure out what is causing the PB to redraw itself without being told to.
If you cannot use the DoubleBuffered than you can HIDE a second picture box. You do the drawing in it and once it's completed you draw back to the VISIBLE one. This way the process of drawing is done on the hidden one and the white/flickering will not be shown.