I have a Delphi 6 application that has a TJvListView control. I have a popup menu tied to that control via the control's PopupMenu property. What I would like to do is show a different popup menu based on which column the user had the mouse over when they right clicked, with the additional option to not show a popup menu at all if the current column does not need one. How can I do this?
Thanks to this detailed sample by Remy Lebeau on in-place editing in a TListView I know what row and column the mouse is over except for one wrinkle. The mouse down event where I determine the current row and column occurs after the popup menu is exited.
I now need to know two things. First, how can I get some event to fire before the popup menu shows after a right mouse click so I can record the current list view row and column and suppress the popup menu if I want to, and second, how I can show a different popup based on the current column. I am hoping to avoid having to write a bunch of mini-forms instead of using the TListView PopupMenu property and supporting code. Is there a simple solution, perhaps some fancy footwork in a sub-class I should create around TJvListView?
You could perform the detection in mousemove instead of mousedown/Click and change the popupmenu depending.
You also could remove any popupmenu and call the wished via p.pupup in mousedown as you desire.
Related
I've been following the below page in order to have a child Form that I can click on its components (such as an edit) and have proper focus:
Working with MDI Forms in Delphi
The problem now is that the components on the parent Form show on top of the child Form. If I use the SendToBack() command for those components, they completely disappear. Here is a screenshot of what happens:
EDIT:
I have a Form with buttons and a ListView that displays client info. When I click on a client, I can click a button to view or edit that client, alternatively add a new one. The Edit/Add pops up a Form where I can input the info and save it. I'm using an OnClick event for each Edit that has a SetFocus(). That gets focus on each Edit, but then all the text is selected, so I cannot click on the line and start editing text - it just overrides unless I use an arrow first.
Initially, I used regular Forms and that's where I had the focus issue. MDI fixed that, but now it's the parent components that show on top of the child.
Concerning MDI forms: that is how MDI works. The main form is not supposed to have anything else than a menu bar and optionally a toolbar, aligned alTop. The child forms use the rest of the space. Well as #RemyLebeau suggested, you can add other controls too, if you align them.
But it turned out that the actual problem with using ordinary secondary forms was that the text in an edit control on the secondary form becomes selected when you set focus to the edit control in a button click. That is easy to change, right after you set the focus to an edit control:
Edit2.SelLength := 0; // nothing selected, cursor at beginning
Edit3.SelStart := Length(Edit3.Text); // nothing selected, cursor at end of text
I have a TStringGrid, that has a TPopupMenu connected.
By clicking one event of the popup menu, I would like to get the calling component. Is that possible?
Background:
It is a bigger project, every form has a "BasicForm" I can inherited from. So I would like to provide a "default popup menu" for grids that have stuff like Copy, Select, and so on in it. In the inherited form I only match the grid (if exists) with that popup and I'm done.
Seems you are looking for the PopupComponent property of TPopupMenu:
Vcl.Menus.TPopupMenu.PopupComponent
Indicates the component that last displayed the popup menu in response
to a right mouse click.
Read PopupComponent to determine which control is currently using the
popup menu. In applications where multiple controls share the same
pop-up menu, use PopupComponent to determine which of them displayed
the menu.
Set PopupComponent to associate a control with the menu before calling
the Popup method programmatically to bring up the pop-up menu.
When clicking on a button I open a popup menu, e.g. using popupMenu.popup().
To select an item I must first release the mouse button and then click on a menu item to execute it.
This is "normal", but what I want is the behavior that I won't have to do an extra click on the menu item. I would like to be able to click on the button, move over a menu item (still holding the button) and execute it immediately after releasing the mouse button.
This is similar to how cascaded sub menus work.
I tried the way using TrackPopupMenu to hook into the messages and execute the item when the button is released. This works, but...
When using images in the popup menu (either bitmap or imagelist items) together with TrackPopupMenu then the menu does not show any entry. Every entry is some pixels wide and empty. You can use them blindly, so they work somehow but the drawing is not done correctly.
I'm using Delphi XE2 Pro.
I also tried to find general articles to hook into menu messages but did not find anything that works without using TrackPopupMenu. Maybe there is a way to have TrackPopupMenu displaying menus with images?
Any help is much appreciated.
You are routing menu messages to the wrong window procedure, you are passing the handle of your form to TrackPopupMenu (you should post your code, then there would be no need to guess what you're doing wrong. And you'd probably receive a much quicker reply).
Forms have menu support for window menus. When a form window procedure receives a, say WM_DRAWITEM, it only draws the item if it belongs to the window menu. For popup menus, VCL uses a utility window which is accessible through the global PopupList. See below example.
var
Pt: TPoint;
begin
Pt := Button1.ClientToScreen(Point(0, Button1.Height));
TrackPopupMenu(PopupMenu1.Handle, TPM_LEFTBUTTON, Pt.X, Pt.Y, 0,
PopupList.Window, nil);
I have a TPageControl that contains five pages and the page shown is alternated setting the ActivePageIndex property in this way:
PageControl1.ActivePageIndex := 4;
the problem is that the page below covered by the page currently shown get click on his buttons while the mouse is pressed on the above page, how can I avoid this behaviour ? How can I avoid the propagation of the click on Pages below the currently shown (that is also the current index)?
The application uses CLX as Graphics library instead of VCL.
Delphi does not do click Propagation.
I would check if the button that gets click are placed on the TabSheet and not on the parent control. Find the button you want in the drop down list of object inspector and press - the selected item will be the parent of the button. Is it a TabSheet?
Or you can add this code as a first line of your button-click-function
ShowMessage(TButton(Sender).Parent.Name);
I have a heavily modified control based on TStringGrid. I want to allow the user to make selections in this grid but restrict the selection one single row (the current row).
Implementation:
When the user presses the left mouse button I am using a dirty hack: On OnMouseDown event I capture the mouse cursor and keep it on the current row. The user can move the mouse device up and down on its pad but the cursor will not go up or down. It will stay on the current row. When the user releases the button (OnMouseUp event), I release the capture.
However, this hack is as I said very dirty. There are several problems. For example, if the user presses the left mouse button (LMB) and then without releasing that button it presses the right button, the associated pop-up menu will pop but the mouse capture will never be released. So, the mouse will be locked in a screen region until the user will has the brilliant idea to click the LMB one more time to unlock the mouse. This may be a bug in D7. There is a separate post about it here: TStringGrid - OnMouseUp is not called!
There is a elegant way to do this?
Edit:
OnSelectCell is not working. OnSelectCell event is called only once when you click the cell. If you keep the button pressed and move the mouse to expand the selection, OnSelectCell will not be called again.
Indeed MoveCurrent appears only in TCustomGrid.MouseDown.
Use the OnSelectCell event and set the CanSelect var parameter depending on whether the ARow parameter is what you want.
A nice solution
Check the options property on TStringGrid
There is an Option called 'goRangeSelect'
Set this to false using the object inspector
Or programatically this can be done by
StringGrid1.Options - [goRangeSelect];
This answer is not elegant at all, but it works.
My solution is NOT to use the PopupMenu property of the StringGrid. Instead I implemented my own PopUpMenu property. Works almost perfect. There is on small problem, the bottom of the pop-up menu appears next to the cursor and not its top.