I'm writing a C win32 application that has a custom text box input with onFocus/onBlur callbacks. This control cannot be changed and I cannot use C++.
As you could guess, I'd like the on-screen touch keyboard to appear onFocus and to disappear onBlur. What's the best way of achieving that?
I was thinking of creating an invisible textbox over it or something along those lines, thinking the OS would trigger the OSK if needed? Should I use UI Automation? I struggle to find C examples of such implementation
Regards
Related
Background: My client has a very extensive proprietary forms library which is effectively implemented in C (actually, it's a proprietary object-oriented language that basically wraps Windows controls and interacts with them with SendMessage(), SetStyle(), etc.)
Problem I want to solve: Whenever I drag/resize a top-level window (or drag a splitter) in an app implemented in the above framework, there is massive flicker. The top-level window is repainted, and any controls it contains repaint themselves.
Question 1: Is there a way to surgically introduce double-buffering into the forms library. In particular, I want to know if I can implement double-buffering using standard Windows GDI functions.
For example, if I could cause the top-level windows to be double-buffered such that all child windows of the top-level window are automatically drawn double-buffered as well. An even better alternative would be to be able to introduce double-buffering on any arbitrary window and have all its children inherit this.
The best solution would somehow cause the BeginPaint() function for child controls to return a handle to the DC of the offscreen back buffer so that I don't have to write special code for each individual control class.
Question 2: Is there a way (such as a set of flags) to cause generic Windows controls (EDIT, BUTTON, and so on) to draw themselves double-buffered? This would be a worse solution than a more generic approach that would just seamlessly give them the back buffer to draw on, but it might also be acceptable.
All help greatly appreciated. Please let me know if I can clarify anything for you.
Look into WS_EX_COMPOSITED, which is an extended window style that turns on double-buffering for the window. It may be enough to set this style on the parent of the controls.
You actually might be able to wrap all your window drawing code with C that executes C#, and that way there is already a double-buffered implementation for you.
How to eliminate flicker in Windows.Forms custom control when scrolling?
I have inherited a large MFC application which contains a CComboBox subclass that overrides OnPaint. Currently it does all its drawing by hand (with lines and rectangles), and renders a combo box that looks decidedly Windows 98-style. However, it otherwise works great and provides a lot of useful custom functionality that we rely on, and rewriting the entire control is probably not an option.
I would like to modernize it so that the OnPaint draws in Aero style where available (falling back to the old code when modern theming is unavailable). I've done this with some other custom controls we have, like buttons, and it works great for our purposes. I know there are some tiny behaviors that it won't get right, like gentle highlights on mouse-hover, but that's not a big deal for this app.
I have access to the CVisualStylesXP ckass, so I've already got the infrastructure to make calls like OpenThemeData, GetThemeColor or DrawThemeBackground pretty easily (via LoadLibrary so we don't force Vista as a min-system). Unfortunately, I don't know the proper sequence of calls to get a nice looking combo box with the theme-appropriate border and drop-down button.
Anyone know what to do here?
Honestly, I don't know why they originally tried to override OnPaint. Is there a good reason? I'm thinking that at least 99% of the time you are just going to want to override the drawing of the items in the ComboBox. For that, you can override DrawItem, MeasureItem, and CompareItem in a derived combo box to get the functionality you want. In that case, the OS will draw the non-user content specific to each OS correctly.
I think you best shot without diving in the depth of xp theming and various system metrics is take a look at this project: http://www.codeproject.com/Articles/2584/AdvComboBox-Version-2-1
Check the OnPaint of the CAdvComboBox class - there is a full implementation of the control repainting including xp theme related issues.
Not sure if it's the same situation - but when I faced this problem (in my case with subclassed CButtons), solving it only required changing the control declaration to a pointer and creating the control dynamically.
Let's assume that your subclassed control is called CComboBoxExt.
Where you had
CComboBoxExt m_cComboBoxExt;
You'll now have
CComboBoxExt* m_pcComboBoxExt;
And on the OnInitDialog of the window where the control is placed, you create it using
m_pcComboBoxExt = new CComboBoxExt();
m_pcComboBoxExt->Create(...)
Since this is now a pointer, don't forget to call DestroyWindow() and delete the pointer on termination.
This solved my particular problem - if your control is declared in the same way, consider giving it a try.
I'm looking to add a 'close' button to my main window's menu. An example can be found in the picture here: http://ifyoucodeittheywill.com/img/crimson-editor.png
(So, there's the normal close button in the window caption area, but, there's also a close button in the window's menu bar -- on the far right).
I'm using basic win32 API's, though an example using MFC would also be fine.
Does anyone know how to do this?
Thanks,
Andrew
These buttons usually come with MDI windows. However I'm pretty sure the depicted application uses either its own, or more probably some advanced third party toolkit. Because, to be honest, what the Windows API and MFC (which is just a classed wrapper around the windows API) give you for GUI programming is unbareably limited.
If you want to design neat UIs steer clear from MFC and better have a look at something like Qt, wxWidgets or the like.
A really simple way of doing this is to use a regular menu item, using AppendMenu, but use the following flags:
MF_BITMAP with a close button bitmap, or MF_OWNERDRAW or to draw it yourself
MF_HELP (aka WM_RIGHTJUSTIFY), a not-very-well documented flag, which will justify the item to the right.
Here's one reference to MF_HELP that I found on msdn - it's actually about using the Win32 API to right-justify a menu item, but using Visual Basic.
MF_HELP (defined in winuser.h) is something of a holdover from Win16 days, back then, the convention was to right-justify the Help menu item, so it would stand apart. It was 'renamed' - an additional #define added with the same value - to WM_RIGHTJUSTIFY around Win95.
Note that bitmap menu items aren't accessible (eg. to users that are relying on a screenreader to read out where they are on the screen); if taking this approach, then at least add a regular 'Close' menu item elsewhere in the menus (eg. under File), so that a user doesn't have to rely on this item, and can also close it through usual means. Also be sure to implement the Ctrl-F4 shortcut, which is what most applications that support multiple documents or tabs use to close the current item.
By all means do not try to create this behaviour yourself. This is functionality that you get "for free" if you are using the MDI architecture of MFC. The close button "next to the menu" as you call it closes the active MDI child window. If you are not using the MDI architecture then there is no point in trying to add a close button there. Can you explain if you are using the MDI architecture?
Is there any way that I can show a window only when a pen/tablet is in use, just like the windows tablet PC input panel is only shown when a pen/tablet is used (and not just connected)?
You can handle or set a trigger for the UIElement.StylusInRange event to make your control visible. (Conversely there is a StylusOutOfRange event which you might need for hiding)
i would like to create a simple winforms or wpf application where i can drag and drop virtual "cards". this below is not exactly what i want to do, but it the closest thing that i found on the web to represent the user interface.
http://www.greenpeppersoftware.com/confluence/plugins/advanced/gallery-slideshow.action?imageNumber=1&pageId=24870977&decorator=popup&galleryTitle=Task+board+and+transitions
so basically i want to have columns in the GUI where i can drag and drag from one to the other.
My questions are:
would this be easier in winforms or wpf
where do i start?
In both winForms and WPF dragging and dropping can be done in a similar way by working with the events on the target DragOver and Drop.
However with WPF you have other options. You will also be able to make the application look better by having a thumbnail as you drag (this is possible in winforms but harder to achieve).
Have a look at this WPF sample it uses a helper class and think it does exactly what you need.
I agree with John in that WinForms and WPF are quite close to one another w.r.t. drag'n'drop. But WPF offers more of a "common base" for ItemsControl, allowing to implement more independent of the final UI elements used (ListBox, ListView, TreeView... can be easily switched). And obviously WPF allows much more fancy effects.
I would strongly recommend this blog post:
http://www.beacosta.com/blog/?p=53
both for some drag'n'drop basics and for a clean WPF drag'n'drop approach.
It shows a nice implementation of a rather generic helper for drag'n'drop from/to WPF ItemsControls, I really like that "Insertion Adorner". And I do like that the drag'n'drop code is nicely separated from the user control itself by using attached properties, which makes it much easier to use and maintain.
It would probably be slightly easier in WPF because of the Thumb control which provides easy to use built-in support for dragging. (If I remember correctly, in WinForms you would need to handle the mouse events yourself, whereas the WPF Thumb does this for you and translates them into drag start, delta and end events.)
However if you are much more familiar with one framework than the other than that would probably dwarf the difference that the Thumb control would make.
You should also have a look around for toolkits/frameworks that could handle this for you -- I think they exist for both WinForms and WPF (not sure though).
A good way for darg and drop are explained as
Detect a drag as a combinatination of MouseMove and MouseLeftButtonDown
Find the data you want to drag and create a DataObject that contains the format, the data and the allowed effects.
Initiate the dragging by calling DoDragDrop()
Set the AllowDrop property to True on the elements you want to allow dropping.
Register a handler to the DragEnter event to detect a dragging over the drop location. Check the format and the data by calling GetDataPresent() on the event args. If the data can be dropped, set the Effect property on the event args to display the appropriate mouse cursor.
When the user releases the mouse button the DragDrop event is called. Get the data by calling the GetData() method on the Data object provided in the event args.
You can find the complete article here