I have a CListCtrl (report style) where I clear the list and repopulate it at certain times. I'd like to maintain the vertical scroll position when doing this. I see there are a couple methods that look promising:
EnsureVisible()
GetScrollPos()
SetScrollPos()
GetScrollInfo()
GetTopIndex()
Scroll()
I'm trying GetScrollPos() and then SetScrollPos() but it doesn't appear to be working. What is the simple correct way to save a scroll position and then later restore it?
UPDATE
Actually it seems I can get to save the scroll position GetScrollPos() and then SetScrollPos() to restore it, however it literally just seems to set the scroll bar position and does not actually scroll the items of my CListCtrl.
UPDATE 2
The Scroll() method seems to correctly scroll the scrollbars and the contents. However it takes a CSize object as it's argument. So the question would be how to translate between the CSize and the output of either GetTopIndex or GetScrollInfo/Pos.
I've done that in the past. IIRC, the trick consisted in:
int topIndex= m_List.GetTopIndex();
RenewContents();
m_List.EnsureVisible(m_List.GetItemCount() - 1); // Scroll down to the bottom
m_List.EnsureVisible(topIndex);// scroll back up just enough to show said item on top
Another way to do it is like so:
CRect r;
m_lcList.GetItemRect(0, r, LVIR_BOUNDS);
int scrollPos = m_lcList.GetTopIndex() * r.Height();
RenewContents();
m_lcList.Scroll(CSize(0, scrollPos));
Related
I am using MVC for my project. And I have few views in View. However, I want to know how to add a scrollbar to one view and only make that part can be scrolled vertically.
I have tried using CreateWindowW() for adding WM_VSCROLL parameter, but it does not work.
This is a TUI application, so I think the professor try to make us using a cell as bar, so you can scroll the cell up and down
In PreCreateWindow(CREATESTRUCT& cs), set cs.style |= WS_VSCROLL;.
You may have to respond to WM_VSCROLL to process scroll messages.
Sorry for the confusing. I am resisted to use TUI only. And I misunderstood what the professor needed. So he wanted us to move a color cell so you can scroll up and down for checking player's moves. I am making a Gomoku Game by using C++. So I figure it out, right now my move list view can move up and down for viewing full moves. Thanks for all the answers
enter image description here
I have a window structured in the following manner:
Window>VBox>Scrolled Window>Tree View>Columns
My issue arises when I label the last column (it must be a dynamic assignment). If the label winds up being too long, the containing window gets stretched horizontally. Instead, I would like a scroll bar to appear at the bottom of the Scrolled Window to deal with it, leaving the window at its original width.
However, it looks like the closest I can come is fixing the height of the Tree View. Surely there's a way to fix the width?
Do you have some code to look at? I have done this many times in python and never had any trouble. Also, you link to the fixed height property of the Tree View rows, you actually need the requested width property of the scrolled window. That link also has a link to set the size of the window.
I am programming a game and I have a tab widget which takes up the majority of the window. I want to use the extra space in the tab bar for buttons. I have the tab widget in a grid layout. To accomplish this, I use the code below in order to remove and add back the button widgets to the desired areas (the solution to someone else's question).
ui->centralLayout->removeWidget(ui->exitButton);
ui->centralLayout->removeWidget(ui->ResizeButton);
ui->centralLayout->addWidget(ui->ResizeButton,0,4, Qt::AlignTop|Qt::AlignRight);
ui->centralLayout->addWidget(ui->exitButton,0,4, Qt::AlignTop|Qt::AlignRight);
This does not work for me; however, because I would like the second widget-- the resize button-- to be just to the left of the exit button. What is occurring is that it instead overlaps the exit button. I simply need to move it 21 pixels to the left and have no idea how!
I tried putting both buttons in a frame and then removing and adding the frame the way I did the buttons. Unfortunately the same functions I used do not exist for the qt frame object.
Here are some pictures of my window.
https://docs.google.com/document/d/17w5USWQcCtb6OdcRShdcYcRjXTcdVpmdrG5TWLX71y8/edit?usp=sharing
you are using void QGridLayout::addWidget(QWidget * widget, int row, int column, Qt::Alignment alignment = 0) overload.
2-nd and 3-rd parameters are row and column of a grid. And you put 2 widgets in the same cell so they are overlaping each other.
I solved my problem. Earlier when I was trying to add them to a frame and reposition it I could not but using a widget as the container for my buttons let me place them the way I was earlier attempting to individually place the buttons.
I got a multiple selection CListBox with horizontal scroll bar enabled and showed correctly. Problem is, that when I use function
lst.ResetContent() and fill it back, I can't find way to scroll text in the rows back to the same position. I tried to use
lst.SetScrollPos(SB_HORZ, horizScroll, TRUE); , where horizScroll = lst.GetScrollPos(SB_HORZ); This works correctly on scroll bar itself, but
text in the row stays not scrolled (manual scrolling functions OK).
Structure of my program is:
CListBox lst;
int horizScroll;
/*Periodically doing code bellow*/
//Get current scroll position
horizScroll = lst.GetScrollPos(SB_HORZ);
//Reset current content
lst.ResetContent();
//Add item into CListBox (UNICODE in my application)
lst.AddString(L"Some longer text then width of CListBox");
//Calculate horizontal extent and set it through
lst.SetHorizontalExtent(calculatedWidth);
//Try to scroll text (scrolls only scroll bar, not text itself)
lst.SetScrollPos(SB_HORZ, horizScroll, TRUE);
UpdateData(FALSE);
Thanks in advance!
EDIT:
As "rrirower" answered correctly,
lst.PostMessage(WM_HSCROLL, MAKEWPARAM(SB_THUMBPOSITION, 250), 0);
message does the job. Scroll position from horizScroll works perfectly. I suggest posting this message twice, because if you do it only once, text is re-scrolled visually from beginning to the wanted position. When you post it twice, text visually stays at the correct position and scroll bar just quickly comes to the right place.
If I understand you correctly, you're trying to scroll the text in the list box horizontally using the program code. If you use Spy++, you'll see that when you manually scroll, using the mouse, a series of WM_HSCROLL messages is posted to the list box control. You can accomplish the same thing by doing this...
lst.PostMessage(WM_HSCROLL, MAKEWPARAM(SB_THUMBPOSITION, 250), 0);
You need to calculate the position (I used 250 above), but, the above code should move the text and the scroll bar horizontally.
After some reading it seems that Invalidate should do the trick. Since as I understand you have one text line this should be fine, however if the painting itself is complex and requires resources you can use ScrollWindowEx and then InvalidateRect on the rectangle returned by the latter to repaint only the changed area.
I have a member of CWnd class name mywindow
and i want to add to it a scroll-bar.
how i can do it?
i try already to do:
mywindow.EnableScrollBarCtrl(SB_BOTH,TRUE);
it display both Horizontal and Vertical scroll-bars,
but i cannot push the buttons or move the scroll-bars.
i try also after the first command:
mywindow.EnableScrollBar(SB_BOTH,ESB_ENABLE_BOTH);
and it change nothing.
can someone could show me a simple example how to add scroll-bar to this member?
thanks a lot,
Tal
Enabling the scroll bars isn't enough. You have to react to the window messages WM_HSCROLLand WM_VSCROLL. Using the GetScrollInfo method you get the position (value) of the scroll bars and then you draw your window content according to this position.
Look up some scroll bar tutorials such as http://www.codeproject.com/KB/dialog/scrolling_support.aspx . In essence, dwo's comment above is what you need to do - handle those messages and set the virtual client area size.
There must be some 'overflow' before scroll bars became active.
Write some 'sufficiently long' data in your view and the scrollbars will become active (at least, that was my experience time ago).
Usually scroll bars get handled 'automatically' from MFC components like (for instance) text editor or form view. I.e. will became visible when needed also without explicit call EnableScrollBarCtrl ...