I have a Form object with a title bar displayed.
I need a pure managed way(P/Invoke-free, both Mono and .NET compatible, preferrably a .NET 2.0 API) to detect when the FORM itself starts being dragged, changes location and when it is dropped(not any content).
I did this in the past in Mono but I don't remember how anymore and I don't know if my solution was MS.NET-compatible...
If anyone could provide an example, three event names for me to google more details or point me to a relevant StackOverflow question, I would greatly appreciate. So far, my search has returned no relevant results...
Are you talking actual drag-drop operation here, or when the user moves the form? If it is the movement itself, you might be able to use the ResizeBegin event, which is raised when the user starts to move the form. This together with LocationChanged and ResizeEnd should cover your needs. However, the ResizeBegin and ResizeEnd events are (of course) also raised when you start and end resizing the form, not only when you are moving it.
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I have a Form object with a title bar displayed.
I need a pure managed way(P/Invoke-free, both Mono and .NET compatible, preferrably a .NET 2.0 API) to detect when the FORM itself starts being dragged, changes location and when it is dropped(not any content).
I did this in the past in Mono but I don't remember how anymore and I don't know if my solution was MS.NET-compatible...
If anyone could provide an example, three event names for me to google more details or point me to a relevant StackOverflow question, I would greatly appreciate. So far, my search has returned no relevant results...
Are you talking actual drag-drop operation here, or when the user moves the form? If it is the movement itself, you might be able to use the ResizeBegin event, which is raised when the user starts to move the form. This together with LocationChanged and ResizeEnd should cover your needs. However, the ResizeBegin and ResizeEnd events are (of course) also raised when you start and end resizing the form, not only when you are moving it.
I tried writing code several different times, but I came to an error with each one.
Basically, I'm trying to make "windows" similar to say Explorer, Paint, MediaPlayer, where you could drag then around, interact with them, minimize and close. Of course, if you clicked on a window, the one below it (they can overlap) shouldn't get affected.
I know how to do this, I have a list of the class I call Window, loop through it, and I only interact with the first window to contain the location of the mouse-click. This way, other windows overlap won't get affected.[1]
Next, I had to make it so that two buttons that are overlapping don't get activated when the user clicks in the "intersection of both buttons." I handled this by using the same method I used above.[2]
But the problem I'm facing now is that, if I hold the left click, but then I decide not to click a button, I drag the mouse away from the button, and release the left click, so that the button-click event won't be activated. But, when I remove the mouse from the boundaries of the button, and say, into another.. the new button get activated. Which it should not.[3]
My set up is like this:
I have a class called Window.
In Window, I have a list of the class called Interface (similar to the Control class in WinForms).
And each Interface has a struct in it that contains 4 bools, if the left/right is currently down, and if they were down in the previous processing. (prevLeft, prevRight, currLeft, currRight)
So, I'm ready to discard that (I have not yet, so I still have the source code), but I need a good structure for making an object-oriented type of application. However, I am not using WinForms. I need help with the structure alone, so no actual code is necessary, description is enough. I need to avoid the 3 problems I mentioned above.
Creating your own Window Manager is not an easy task. I know it because I'm making one too ;)
You can use an existing, though maybe not the best solution, like for example Nuclex.UI, which I personally rejected when I first saw it, but if you're not dead set on making your own WM, I suggest to use that or hybrid WinForms-XNA approach.
But if you're really dead set on implementing a custom Window Manager, you have to understand how any other WM works. Since we're talking about XNA, it means Windows, and that means Windows Explorer, which is a great thing to learn from.
You have to recognize how the simplest things work, and it's really not so hard. The hard part is figuring out what logic is updated when, and how to not spend all the CPU on only UI updates. Let me just give you a few hints on how to solve the problems you mention in your question.
To keep track of all windows, I'm using a Dictionary<string, Window>, where Window is a custom class, and the string is its unique name for rare cases where I have to call windows by name. Think of it as a window GUID or Handle. But you can just make it so that a "Form" can only appear once, and store all references in static variables.
To make WM understand what control you're clicking I use rectangles and check if they contain a Point which is at Cursor coordinates and has {1; 1} pixel size, which is probably about the same way it's done in Windows Explorer. To do that your WM needs to know in which order to update the active windows. Usually you'd want to start from the topmost window and continue towards the end of the list of active windows. For that you can just iterate through the list with a foreach loop.
But that's not all, because every window itself is a Container, which means it contains other controls, some of which may even be Containers themselves, like WinForms Panel class. This means you have to iterate through each of the Windows' Children controls. The update order should make sense too - update from the topmost child to the bottommost, recursively for Container controls, in case they also have Containers in them. This basically means you'd want to implement a recursive GetAllControls() method for your WindowManager class that would iterate through all Containers and return a list of all Controls.
Drawing all those Controls should be done in reverse order of updating them, so you can just GetAllControls().Reverse() and iterate through that in a foreach loop.
Where to draw and what to update depends on all the parent containers the current container has and their combined offset from the top-left corner of the game window. I solve this by storing a ParentContainer reference in all children controls to get the appropriate DrawRectangles and update areas via recursive properties.
When you click somewhere on the screen and a click is registered on a Control, make the WindowManager remember that (bool clickRegistered) and not run any OnClick events on any underlying Controls.
Windows Explorer remembers the control you clicked and will activate its OnRelease event if the cursor is then released in the update area of the very same control. So basically Windows Manager only does something when you release the mouse button. You can make your WindowManager and Controls to handle click events differently, like firing an event right after you press the mouse button, i.e. OnMouseDown. But remember that Microsoft aren't noobs and there's a reason for that behavior in Windows Explorer, and it's because if you accidentally press a mouse button somewhere you didn't intend, you can still fix it by moving the cursor outside the pressed control's update area and not run its action.
At this point you might be thinking "Is it really worth implementing all this?" For me the answer was "maybe", because I was a total noob in both C# and XNA at the time I started, and now I know my game, which was originally supposed to use some Window Manager, is going to benefit from my own WM implementation far more than from ready third-party solutions. And besides, it's a great exercise in logic and programming.
But if you'd like to think of yourself as a game developer, you should think in terms of reaching your goal as quickly as possible, i.e. actually making a game, and not the game engine. So in this case, better make use of existing solutions and start selling your product.
Instead of having the structure with the 4 booleans (similar to xna), how about you make a way to tell where the mouse "is." So in a sense, the mouse is in Window number 5 which is Paint, and the user is holding the mouse down on interface/control number 2 which is a button.
That sounds like it could work.
My question is very general, I'm making a project and referenced two projects(graphsharp and wpfextensions). These are helping me to create graphs.
When I created my graph for example I can easily drag the vertexes or move the graph by clicking the empty space in screen etc..
But I do not know what is happening in background, for multitouch capabilities, I need to find what is going on when a mouse event raised.
Therefore my question is how to find these events and methods in a lot of source files ?
Thanks.
The question does really general and fuzzy but probably some tool like Snoop http://snoopwpf.codeplex.com/ will help you (here you can take a look how it works and looks http://blois.us/Snoop/). There is "Events" tab for selected part of UI of your application where you can investigate all the way of Event through a visual tree and see who (which control) has handled this event. Then you should check the control that handled this event and see if it's something you are looking for.
I know that when a drag/drop operation is completed, upon receiving a MouseUp or Esc key event, it returns an enum that indicates what happened (Move, Copy, None, etc.) My question is this: is there a way to send back status information to the form/control that initiated the drag event, while it is going on?
The use case is as follows (think Visual Studio-esque layout manager for all of this): I am writing a layout/window managing component that allows regions of the layout to be dragged around. I use a transparent form to paint a semi-transparent overlay that changes based on where the mouse is dragging over, a la the preview overlay that appears when dragging windows around in Visual Studio.
Another motivation is that the serialization process I describe is relatively resource intensive, and I'd prefer not to do it if the dragging is all going to occur within the same process/window. So, if there was a way to lazily serialize only when an actual "drop" in another window happens, that would probably make all the difference in usability.
What I want to do is enable dragging between different windows or even different instances of the application. I've already plumbed out the serialization code and everything, but the issue is that, when I drag a chunk of layout into another window, the first window doesn't have any way of knowing that the mouse is now over another instance of the application, which is more than capable of painting its own overlay. So, the original overlay hangs around like an idiot and my program looks like crap.
Is there any way for me to pass along some kind of callback or is there any message or property I can listen for/poll during a drag operation that will tell me if my mouse pointer is over a region that can accept its data? Please don't make me resort to listening for the CursorChanged event, I've already lost too much self respect using reflection to hack around weird wpf/winforms dragging interop bugs. If anyone could suggest a clean resolution for this problem I would be extremely grateful.
Additionally, if anyone could point me to any favorite sites which describe how to go about doing reeeeally funky things with drag and drop, it would be appreciated, as I've found there is quite a lack of really nitty gritty information available about dragging. Usual things like custom cursors and the like are okay, but I'm probably more interested in Win32 black arts and the like.
UPDATE:
I actually just found out about the GiveFeedback event a second ago, came back to my question, and there it was. Huge facepalm moment. However, since I've got you here, what about my second question: is there any way to lazily load the information only when it encounters a valid target? Could I somehow implement my own IDataObject or do things get marshaled righ when the mouse leaves the form? GiveFeedback provides me only with whether there's a valid target under the cursor, but doesn't let me change what data is being dragged...
ANOTHER UPDATE:
Is there any way to determine the source of a drag operation? That is, when my control receives a DragEnter message, how can I tell if the source of the drag is my own control or a foreign one? I know I can hackishly encode it by messing with the AllowedEffects property, but is there any more direct route?
Check out the GiveFeedback event (there's a nice article here) - that sounds to me to be exactly what you're after.
Facing an issue where in the user objects goes more that 10000 in windows app and the app crashes.
After much analysis we realized that we need to get rid of the panels that we use to align the controls and may be reduce the possibility of user objects reaching 10000.
Our App UI is dynamically generated driven by a configuration and it can vary. So all the UI generation is happening dynamically.
Any help would be much appreciated
This is an unfounded suggestion, but remember to make sure that unneeded Controls always detach themselves from events they are be subscribed to. A Control that's still subscribed to an event of an "active" (what's the right term?) object can't be cleaned up.
Just as a note, the Chrome development team hit this problem too, and the scroll bar arrows (among other things) weren't drawing anymore when some internal gdi limit was hit. It is quite possible to hit this limit in a complex enough gdi app.
You might want to do some research and see how they fixed it.
As an alternative, you could consider using a different platform, either gtk or wpf would do fine and they don't use gdi handles to draw.
from here,
If your program runs haywire, you will
find that it manages to create about
10,000 window manager objects and then
the system won't let it have any more.
Why stop at 10,000?
The first answer is "If you have to
ask, you're probably doing something
wrong." Programs shouldn't be creating
anywhere near ten thousands window
manager objects in the first place.
There is no need for that many handles. I think you need a new solution.
I'm guessing this from your question, but you're probably putting this large number of controls on a scrollable panel or a tab control with multiple tab pages, which means that most of these controls aren't actually visible to the user at any given point in time (because they couldn't possibly all be visible at once).
If you have all of these controls on a scrollable panel, one possible solution is to only load and display the controls that are on the visible portion as the user scrolls around in the panel. As the user scrolls, you would unload and dispose the controls that are no longer visible.
If you have all of these controls in a multi-page tab control, you can use a similar strategy and only load the controls on a tab page when that page is made visible (and unload the controls from the previous top-most tab page at the same time).
Another general strategy is to break up your one monster form into a large number of UserControls, and only show one of these UserControls at a time.