Here is the problem:
The way the GUI system I'm using works is as follows:
A widget can listen to mouse events. The listeners can consume an event they are listening to and as a result, the widget they were listening to will not receive the event, even if it was intended for them, only the listener will have received it.
The problem comes in here:
A scrollpane has a ListBox inside. The listbox can be scrolled. The Scrollpane can also be scrolled. What happens right now is when I mousewheel and the widget under the mouse is the listbox, both the listbox and the scrollpane move. The only solution I see is that the scrollpane consumes all mousewheel events, but then there is no way for the ListBox to ever be scrolled.
The behavior I desire is for the ListBox to scroll when it has focus, but if I did this, it would not work because for example if a radio button inside the scrollpane is focused, I still want the scrollpane to scroll, it is only for widgets with scrollbars such as textbox and listbox where this is not desired.
Thanks
Also, the gui system I'm using is my own which I'm developing.
The usual way to deal with this is that the ListBox only consumes the event if it actually scrolls. If you place the mouse in the listbox and use the scrollwheel the listbox scrolls until it reaches its scroll limit. After that further moves of the wheel cause the scrollpane to scroll.
Obviously there are variants on that - the important thing is to decide what you actually want to happen.
You also need another way of scrolling the scrollpane, so that if the user explicitly wants to scroll it they can, without having to scroll to the end of the ListBox. Scrollbars on the ScrollPane would be one way. You should also make sure there is a way of scrolling the ListBox without using the mouse wheel.
Related
Using C++, I am making a Tic-Tac-Toe game using the Win32 API. To mark a square (X or O) I want the player to click the square which then changes to an X or O.
What I am doing right now is having a button click event which turns a static text box to X or O. However, when I place the button on top of the text box and make it not visible, I can't click it.
What I really need is an invisible button that still functions. So it's not set WS_VISIBLE, but you can still click it.
Is this possible or is there another way around this problem?
I can see a couple of reasonable possibilities here.
The first and most obvious would be to skip using a button at all, and just have the underlying window process the WM_LBUTTONDOWN message, and set the "X" or "O" in the correct location. For this, you don't even need static controls -- you can just detect the mouse clicks directly on the parent window, and draw your "X" or "O" in the corresponding square.
Another possibility would be a button that's marked as "visible", but happens to be transparent. IMO, this is a fairly poor choice though. To do it, you'd need to either create a transparent button control on your own, or subclass a button control to disable its drawing.
At least IMO, the obvious route would be to skip using the static control at all. Instead, just use the buttons directly -- a button normally has a caption. Start with that caption as an empty string. When the button is clicked, change its caption to "X" or "O" as appropriate. It should probably also disable itself in response to the button click, so clicking it again won't have any further effect.
There's no way to make an invisible button that still functions. Imagine all of the ways that could be abused if it were possible! Not to mention how confusing to have invisible, yet functional, UI.
What Mark Ransom posted is exactly right: you need to get your existing control to respond to mouse click events, just like a button does. Then you can do whatever you want in response to clicks. You don't need a button just to be clickable.
You say that you have a "static text box", but I'm not really sure what that is. There are text boxes (which are not static), and then there are static controls (which can display text). I'm going to assume that you have the latter.
In that case, you don't need to handle the WM_LBUTTONDOWN and WM_LBUTTONUP messages directly, which would require that you subclass the control. Although that's probably the best approach design-wise (separation of responsibilities and all that), it's also a lot more trouble.
Instead, you can handle the click events from the parent's window procedure by setting the SS_NOTIFY style for your static control (you can do this either in the Dialog Editor or in your call to CreateWindow, depending on how you create the control). This causes the control to notify its parent in four cases: when it is clicked (STN_CLICKED), when it is double-clicked (STN_DBLCLK), when it is enabled (STN_ENABLE), and when it is disabled (STN_DISABLE).
So at the parent, you need to process WM_COMMAND messages. The message you're looking for will have a HIWORD(wParam) of STN_CLICKED (indicating that a static control with the SS_NOTIFY style has been clicked), a LOWORD(wParam) corresponding to your static control's ID (set either in the Dialog Editor or specified as the hMenu parameter in your call to CreateWindow), and an lParam containing a handle to your static control.
If you use SW_HIDE, it doesn't just make the window invisible but makes it behave like that too. What you really wanted is probably just make the button transparent. I never did that, you may find this or this helpful.
You may just scrap the textbox just use the button, i mean a button-looking checkbox with ownerdraw or bitmaps. Or scrapping the button and handle the mouse events Like Mark suggests.
I have a modeless CDialog that contains controls, some CButtons and a CScrollbar. The CDialog is parented off of an edit box that I want to keep focus at all times. The problem is that whenever the user uses the controls, clicking a button or on the scrollbar, the control steals focus from the edit box, causing both the parent window to draw without focus (grayed-out header bar), and causing the control to take all the keyboard input. Is there a way for the controls to respond to mouse actions but not steal focus?
The controls and the dialog are all created with WS_CHILD. The controls are parented off the dialog, and the dialog is parented off of the edit box.
I've tried setting focus back after the controls are used, but that causes the parent window to flicker as it loses and then regains focus. Basically I want something that works like a combo box, where the scroll bar can be clicked or dragged around, but keyboard input still goes to the dialog itself, not just the scroll bar, and the whole thing never loses focus.
I haven't done anything like this for a long time, so I'm sure there are a million little details, but I think the starting point is to override the handling of WM_MOUSEACTIVATE.
I am a little confused about child-parent relationship you described.
Can you explain what do you mean by:
The CDialog is parented off of an edit box that I want to keep focus at all times
Any window hosting other windows inside of the client area is a parent of those windows. It is impossible to create window without WS_CHILD that is contained by other window.
Therefore all dialog’s controls are children of this dialog. It is also possible that child window hosts another child window.
CDialog is just an MFC representation of a dialog window; the same applies to other controls. For example CButton is an MFC class that wraps handle of the window’s window that is predefined as window button control.
Dialog never has focus unless is empty (does not have any controls). If dialog contains even one control, this control always has focus.
What focus means is that any given window receives mouse and keyboard messages. Only one control can have focus at any given time. In order for scroll bar to process mouse click or keyboard to move slider, scroll bar must have focus; therefore some other control must give it up.
Combo box drop box (I think this is what you are referring to) is not a child of the dialog. It is a popup window that for the duration has keyboard focus and captures mouse. When it drops down, dialog is deactivated and once dropdown hides, dialog state is changed back to active hence focus never changes, it returns to the control that had focus when dialog was deactivated.
What you are trying to do is probably possible but it would require a lot of coding. Probably hooking messages would do the job but I think it would be going against the stream.
Right now, my scrollbar is made up of 3 buttons (its children). The buttons currently consume mouse down, up, click, and drag. The scrollbar then hooks into these 3 buttons and does what it wants them to do. Therefore, I do not use the new bubble-up-the-stack feature of my GUI in this scenario.
I'm still not quite clear on when I should use this and when I should listen to child events.
Is my current technique a good way to do it, or should my button instead not consume these events and receive events intended for the buttons and do stuff based on that?
Thanks
In this case the 3 buttons (I presume up, down, and slider) don't have enough information to do anything on their own; the best they can do is interact with the main scrollbar control and tell it what modifications it should make. In that case it might just be cleaner to have the scrollbar do all the message processing itself. It already needs to deal with things like arrow keys, correct?
I'm trying to create a popup menu like control that contains custom widgets. I need to capture the mouse, but I need to have the children in the widget still get their mouse messages. It appears the grabMouse sends events only to the widget that grabbed the mouse, not its children.
The popup is simply a series of buttons (using a QGridLayout). The control should work that the user presses the right-mouse button, the popup appears, they move to an item and release the mouse button. Optimally it would work exactly like a QMenu popup but with custom widgets and a custom layout.
How can I achieve this?
It appears that simply specifying attribute Qt::Popup is enough to get the fundamental behaviour required.
Installing an event filter on all children is also necessary. All mouse events, enter/leave/hover events must be captured. QT has a defect with grabMouse so that won't work -- the filter must be used to get expected behaviour.
I have an application that has a list of buttons and has customized tooltips. Whenever the mouse hovers through the buttons, the tooltips come out and is working fine. However, I want to hide the tooltips when the mouse cursor is outside the client area. How can I tell my application that the mouse is already out of the client area, when the mouse events I have are limited to the client area alone?
Thanks...
You use TrackMouseEvent, this will send you a WM_MOUSELEAVE message when the mouse leaves your window.
Or use GetCapture(), that's what I always do.