Make a wxWidgets panel always repaint when it is resized - wxwidgets

I have a subclass of wxPanel inside a toplevel window with a couple of levels of wxSplitter above it. When the window is shown the some resizing and layout takes place. When it finishes the background of my panel has random junk (either black or other parts of the window) over some of its background. This seems to be a bug as it's using the bliting that is typically used to speed up scrolling, except that it's bliting from a location that doesn't belong to that panel.
Anyway, I figure I can fix it by making the window always repaint on resize and always draw the full contents of the wxPanel without any blitting. So: Is there any way to make it so the background of the wxPanel is always redrawn in full?

You can try wxFULL_REPAINT_ON_RESIZE style for your panel, see wxWindow docs.
Another way is to catch wxEVT_SIZE and call Refresh() for the relevant panel (and maybe even Update() after it although be careful as this will become a rather expensive op).

Related

Allow user to resize window such that Gtk3 TextView component can't show all text

I'm working on a GTK program in Rust (someone can probably answer this if they don't know Rust, as I can figure out how to translate between different bindings and the native C API) via the gtk-rs bindings for which I want to have a non-editable TextView who's contents are constantly updated in my code. I want the user to be able to resize the TextView to any size, after which my code will re-calculate its contents accordingly. Unfortunately, GTK prevents any resize from taking place that would hide any contents that are current in the TextView. I can't use a ScrolledWindow because I don't want visible scrollbars, and disabling the scrollbars on a ScrolledWindow prevents the resizing behavior that I want. I also tried calling set_size_request to set the size to both 1, 1, and 0, 0 after every text change, but this does not change the behavior at all either — the user still can't properly resize the TextView (by resizing the window).
How can I enable the resizing behavior that I want?
Probably this is not possible. What would be the point of resizing the text view smaller, if the user can never see the text that is outside of the viewport because you don't want scrollbars? That seems like it would confound the user's expectation of how such a component would usually work.
Maybe an approach could be that you pick a certain number of lines to show, make that the size of the viewport, and delete the old contents of the text view that scroll outside of the viewport?

winforms - usercontrol with dockstyle fill not correct size during form load

My main form has two panels, left docked and right docked. The right side panel has two child panels with top dock and bottom dock settings. The usercontrol is added to the right side top panel.
My usercontrol has a panel and a label. The panel is anchored on all 4 sides, the label is anchored on all except the bottom. At runtime I create this usercontrol and set it to dockstyle=fill and then I add it to my top right panel.
With everything set to "fill" I expect that when I add my usercontrol to the panel it will take on the appropriate width and height and pass that info to the child controls (labels) inside of my usercontrol.
My problem is that this stretching of the size does not happen when I create my objects during the Load event on my usercontrol. Even though initializecomponent has ran for the usercontrol the panel inside of it (4 corners anchored) has not taken the x/y values of the available space. As a result my usercontrol shows up about 50% of the width I want.
Lets say that instead of creating objects during usercontrol load that I instead start a timer and have the timer call my create routine when it raises the tick event. When I do things like this my objects are created with the full width/height that I expect. The only issue here is that this causes a delay in my interface.
Can someone help explain this behavior? My mainform is calling a "load gui" routine which is instantiating usercontrols, setting panel sizes, and then adding usercontrols to those panels. This particular user control is the last to load into the panels from that load gui routine so it does not make sense that the parent panel width/height would not be known yet. This is one of my first apps where I am purposely trying to use dockstyle=fill to keep things consistent across different main form sizes without writing all the extra size_changed code handlers. I'm sure this one is easy to work around once I know where the problem lies.
Thanks for any help provided!
this turned out to be a padding issue on the parent usercontrol. I also had to allow a bit of wiggle room to make sure that the controls didn't overflow the panel so I did a parent.width - 15 and that along with the padding made everything work much better.

Cocoa - NSWindow animation when displayed?

How would I add some sort of CoreAnimation effect when showing a simple nswindow?
Thanks
I've done an animation like you describe before. However, it wasn't an easy task. Since your animation extends outside the bounds of the window itself, you'll need to render the animation in an oversized, transparent window. When the animation completes, you can order in the real window and remove the transparent one.
You'll need an image of the window to use as the content of your animation, so what I would do is order the window in (and probably make it the key window, too, so that it looks focused), but put it well off-screen so the user doesn't see it. Then use CGWindowListCreateImage to grab a screenshot of the window. Now you'll have what you need to create an animation.
After the animation completes, just order the real window over top of the transparent one, then remove the transparent window. Getting the math right so that the image of the window in the animation and the real window is a bit tricky, but it's definitely doable.

How can I show scrollbars on a PictureBox control?

Sometimes, I have a picturebox lets say 100x100. But the image it will display is actually 100x400.
I don't want to increase the size of the picturebox itself. Instead, I would like to create a vertical scrollbar (or horizontal if needed).
I could not find a scrollbar in the toolbox, so I guess I have to code it. But, how?
And I still wonder if I didn't make a mistake and didn't see the scrollbar in the toolbox. My apologies then :(
I suppose you could add separate scrollbar controls and sync their Scroll events up with the offset at which the picture in the PictureBox is drawn, but that sounds like actual work. There's a better way.
Add a Panel control to your form, and set its AutoScroll property to "True". This will cause the control to automatically show scrollbars when it contains content that lies outside of its currently visible bounds. The .NET Framework will take care of everything for you under the covers, without you having to write a single line of code.
Drag and drop your PictureBox control inside of the Panel control that you just added. The Panel control will then detect that one of its child controls is larger than its visible area and show scrollbars, thanks to the AutoScroll property. When the user moves the scrollbars, the portion of the image in your PictureBox that is visible will be automatically adjusted. Magic.
(The reason you have to use a Panel control as a container is because PictureBox does not inherit directly from the ScrollableControl base class, which is what provides the AutoScroll property.)
I tried this and it worked well. But I noted that if the picturebox is docked in the panel, the picturebox is automatically set to the size of the parent panel, and can't be set larger (at least not in any way I could find). This defeats the purpose of the technique. So -- put the picturebox on the panel, but don't dock it, and it will work perfectly.
There are no automatic scroll bars on a picture box, but you can add the VScrollBar (and HScrollBar) control to the form and handle the image scrolling manually by redrawing it at a different offset each time the Scroll event is fired.

How can I remove the "blur" effect that Cocoa adds to transparent sheets?

By default, Cocoa adds a background blur effect to transparent and semitransparent modal sheets when they are applied to a window. I would like to disable the blur effect. How would I go about doing it?
I have created a custom sheet (a subclass of NSWindow with a transparent background and some controls in it). I am able to display it using the standard beginSheet method as follows:
[NSApp beginSheet:myCustomSheet
modalForWindow:mainWindow
modalDelegate:self
didEndSelector:...];
The sheet displays fine, but everything behind it is blurred.
Note 1: I am writing a completely customized user interface for a touch screen / kiosk type app, so none of the usual Apple user interface guidelines apply.
Note 2: I do want to see what is underneath the sheet. As SirRatty pointed out, it is possible to block out the blurred portion by filling in the background. In my case, I want to have the background show through, just without appearing blurred.
There's a private API call that can be used to set a CI filter on the background of a window:
http://www.mail-archive.com/cocoa-dev#lists.apple.com/msg16280.html
There's also a CGSRemoveWindowFilter:
extern CGError CGSRemoveWindowFilter(CGSConnectionID cid, CGSWindowID wid, CGSWindowFilterRef filter);
Just be aware that the usual private API caveats apply (might go away or change in the future, etc.).
What I've done:
In IB, add a window-sized custom NSView to the window, at the bottom of the content view hierarchy. Set the object's class to MySolidView (or whatever.)
In Xcode, the MySolidView class does just one thing: on -drawRect it will fill the view with a solid color. (e.g. light grey).
You could write your own sheet animation routines that display your own NSWindow and fill the background of the window with a semitransparent colour. I'm not sure whether setAlphaValue: for NSWindow will also affect the child elements' opacity. If it does affect them, you could use setBackgroundColor: and provide the default window background colour but with an alpha component, this should not affect the child elements.
I suppose one of the problems of developing/designing your own user interface is when you have to reimplement the wheel just for a minor customisation. At least, if you write it yourself, you'll have more control over its customisation in the future.