I am creating a TextBox control subclass using Windows Forms. I am using the WM_NCCALCSIZE to change the client area (to enlarge the non-client area) but I have not found any solution on how to make the non-client area transparent.
Is there any simple way to paint to non-client area in WM_NCPAINT in transparent way to duplicate the underlying window's background in intersecting region of the child control?
UpdateLayeredWindow is what you need.
http://msdn.microsoft.com/en-us/library/windows/desktop/ms633556%28v=vs.85%29.aspx
http://msdn.microsoft.com/en-us/library/ms997507.aspx
Related
I have to crop some control to show only a half of it but the rest should be transparent and clickable so it is not enough to cover the control with something. The result should give a control with only half of the content (for example 50% of top) and the rest should be cropped (not hidden) so some other control below should be visible and not overlapped by cropped part. New control should also scale when window is scaled. How to do this in WPF?
I have finally did the trick using Border around the control and Clip property of this border was set to Multibinging that was generating Rectangle basing on ActualWidth and ActualHeight of my control
Maybe GridSplitter:
http://www.wpf-tutorial.com/panels/gridsplitter/
Can be used to split views horizontally/vertically, and can be responsive.
I'm working on a mapping application and I'm trying to get resizing in X11 working the way I'd like. Conceptually, I'd like my window to be a viewport onto some real-valued space where my data lives. When you resize the window, the size of your view onto this real-valued world should change accordingly.
What this means is that when resizing the window, rather than shrinking/stretching the data, more or less of the underlying window becomes visible. It's easy to handle the case when the window is resized by growing/shrinking on the bottom/right, but I'd like to handle the case when it's resized on the top/left as well.
This is trickier, because a top/left resize also moves the window's origin as well as it's dimensions. I need to detect the change in the origin so that I can compensate to keep my data centered as the window is resized.
Is there a robust way to get the absolute coordinates of a window in X11? The coordinates that X11 reports directly through ConfigureNotify and XWinAttributes are dodgy due to window manager reparenting.
In Xlib use XTranslateCoordinates to translate the coordinate (0,0) in your viewport window into coordinates of the root window. This also covers the case of a stacking window manager messing with your window position.
I could begin by asking the question outright or by citing my sources (this, this, this, and this) descriptively, but I'll walk you ll through what I'm trying to do instead.
Let's start with a main window. It has its own window class whose hbrBackground is set to COLOR_BTNFACE + 1. Now let's do
EnableThemeDialogTexture(hwnd, ETDT_ENABLE | ETDT_USETABTEXTURE)
so the tab control we're about to add will be drawn with visual styles. (Try Windows XP with the standard Luna theme for best results.) Now let's add a tab control and two tabs.
On the first tab, we create an instance (let's call it container) of a new window class. This window class is going to hold various controls. I could set hbrBackground to COLOR_BTNFACE + 1, but then it will draw over the tab background. So I want this new child window to be transparent. So what I do is
set the class hbrBackground to GetStockObject(HOLLOW_BRUSH)
set container's extended style to WS_EX_TRANSPARENT
set the class WM_ERASEBKGND handler to do SetBkMode((HDC) wParam, TRANSPARENT); return 0; to set the device context and have Windows draw the transparent background.
So far so good, right? I'm not sure if I'm really doing all this correctly, and I'd like this to also be flicker-free, which doesn't seem to happen: when I resize the window (at least in wine) I get either flicker or garbage drawn (even in child controls, somehow!). Windows XP in a VM just shows flicker. I tried tweaking some settings but to no avail.
But wait, now I want to have another control, one that just draws some bitmap data. On the next tab, create another container, then have a third window class area as a child of that. area only draws in the upper-left 100x100 area and has scrollbars; the rest of the window area should be transparent.
Right now, what I have for area is:
the window class hbrBackground set to NULL and styles CS_HREDRAW and CS_VREDRAW set
the extended window style being 0
the WM_ERASEBKGND simply doing return 1;
the WM_PAINT filling the entire update rect with COLOR_BTNFACE + 1 before drawing, and rendering all of it
This is flicker-free, but obviously not transparent. NOW I'm really not sure what to do, because I want the area to be transparent in such a way that it shows the tab control background. Again, I tried tweaking settings to bring them closer to what I tried above with container, but I got either flicker or invalidation leftovers when I tried.
So how do I get both of these custom control types (the container and the drawing area) to be both flicker-free and transparent?
I presently must target Windows XP at a minimum, though if the solution would be easier with Vista+ only I'd be happy to keep that solution on the side in case I ever drop XP support (unfortunately Stack Overflow doesn't let me hand out silver medals...).
Thanks!
To paint your window in a manner that is "flicker free", you will need to paint your window to a bitmap, then copy the bitmap to the destination device context. On Windows XP, you will need to create a bitmap, adjust the origin of the drawing DC and then paint your window. On Vista and later you can use BeginBufferedPaint and its associated routines to do the buffering for you.
Once you have buffered painting working, you can then use WM_PRINTCLIENT to paint your window's parent window into the your drawing DC before you do any actual drawing. Unfortunately, not all windows will support WM_PRINTCLIENT.
You could consider using DrawThemeParentBackground, rather than WM_PRINTCLIENT directly.
Combining these two methods together will leave you with transparent flicker-free drawing.
I want to change the font size of a TreeView control. After searching on goolge, I just get some idea that one should use CustomDraw for this TreeView. But NMTVCUSTOMDRAW structure only has clrText and clrText which set the foreground and background color of the displayed texts in TreeView.
My questions are:
Q1: How to change the font size in a TreeView? For the background color of TreeView,
one can just use `TreeView_SetBkColor` or send a message. Anything similar
for font size?
Q2: What's the difference between Custom Draw and Owner Draw?
Q1. You can do this with the WM_SETFONT message.
Q2. They do similar things. Owner draw is an older system and means you have to draw the entire control yourself. Custom draw is newer and more flexible, letting you handle just parts of the drawing if you like (or even no drawing, and just changing fonts/colors).
I would like to understand the general requirements for WPF/Silverlight layout for making it possible to implement pan&zoom (drag and zoom) features. I don't mean pan&zoom for an image but for a total page (window) layout (or part of it) with some controls.
What features of the layout and what features of used custom controls make layout fixed and pan&zoom impossible?
General rule
With few exceptions, everything in WPF can be panned, zoomed, rotated, stretched, etc to your heart's content. This include single controls like Button, compound controls like ListBox, and containers like StackPanel.
The exceptions
Here are the exceptions:
If you are using Adorner and your AdornerDecorator is outside the panned/zoomed area, then the Adorners attached to your panned/zoomed area will pan but not zoom. The solution is to put an additional AdornerDecorator inside the panned/zoomed area.
If you use a Popup, it will display at the panned/zoomed location of its PlacementTarget but it will not itself be scaled. It will also not move as you pan the area containing its PlacementTarget (basically it sits in its own surface above the target control). To get around this, use a zero-size Canvas with high Z order instead when you want something to pop up within the zoom/pan area.
Any ContextMenu you define will be shown inside a popup, so the menu items will display normal size even when the area you clicked on is zoomed in or out. Because of the nature of a context menu, this is probably desirable behavior. If not, you can wrap the menu items in a ViewBox and tie the zoom to your main area's zoom.
Your ToolTips will display normal size even if the UI is panned or zoomed. Same solution as for ContextMenu.
If you used WinForms integration to integrated legacy WinForms controls and UI, they will not properly pan, zoom and clip in certain situations. There is an advanced technique for working around this, where you implement the WinForms control off-screen, then using BitBlt or similar copy the image into your window as an image, and forward mouse clicks and keystrokes to the offscreen window. This is a lot of work, though.
If you bypass WPF and directly use GDI+ or DirectX, or use Win32 hWnds to display content or UI, that content or UI will not be properly panned, zoomed or clipped to the window unless you do it yourself in your interface code.
Final notes
A good WPF UI always uses panels like Grid, DockPanel, etc to lay out controls in a flexible manner so they automatically adjust to container sizes, rather than using fixed sizes and positions. This is also true for the internal contents of your pan/zoom area as well, BUT there is an exception to this rule: the outermost element in your pan/zoom area must have a specified size. Otherwise what will define the area being panned/zoomed over?
The easy way to implement pan/zoom capabilities is to adjust the RenderTransform of the outermost control in your pan/zoom area. There are many different ways to implement controls for panning and zooming, for example you could use toolbar buttons and sliders, scroll bars, mouse wheel, spacebar+drag to pan, draggable areas of panned UI itself, or any combination of these. Whichever interface you choose, just have it update the RenderTransform appropriately from the code-behind and you're good to go.
If your chosen panning mechanism is scroll bars, you might want to use a ScrollViewer and only use the RenderTransform for the zoom.
Be sure you set clipping on the pan/zoom area. Otherwise if you zoom in or pan items off the side, they will still be visible outside the pan/zoom area.
Use a MultiScaleImage or Canvas area, and place everything you need to pan and zoom in it
<Canvas x:Name="panZoomPanel" Background="Transparent">
</Canvas>
In code use make a TranslateTransform and a ScaleTransform in a TransformGroup to pan and zoom
Check out other SO post or this example or this one
In general you can treat any composite set of UI elements the same as you would treat a single UIElement so the case of an image isn't really different than doing the same for an entire application. The best way to handle zooming based on user input (as opposed to automatic scaling that Viewbox does) is applying a ScaleTransform. This can be set on a high level parent element, like a Grid at the root of a Window layout. For panning you can combine in a TranslateTransform or in some cases use a ScrollViewer to handle moving the view of the content.
One really easy way of implementing zoom in XAML is to use a Silverlight ViewBox. This zooms the XAML not the pixels. You can specify the stretch to use and the ViewBox will scale based on this (Fill, None, Uniform etc). There are some great Viewbox blog posts on the web if you search for Silverlight+Viewbox on Google.
The panning is easily accomplished with a similar mechanism to drag and drop and there are also numerous how-to blog posts on this, available via Google. Just amounts to capturing MouseDown, MouseMove and MouseUp events.