I am using NM_CUSTOMDRAW to draw tree view items. My items right justify parts of it by using a right margin based on the RECT area reported available. The issue I have is that when the vertical scrollbar appears or disappears, only the item expanded/collapsed and the area under the scrollbar seems to update (invalidated regions). This causes the repaint requests (with the new width) to not update the area correctly.
For example (using text and a single space as example): You could have something with the scrollbar be right justified text ## where ## is the scrollbar then when the scrollbar goes away you end up with right justified text t instead of right justified text
Is there a good way to fix this?
One thought is if I could catch a message when a scrollbar shows up or goes away, I could just invalidate the window to force a redraw. Is there such a message?
Or is there a way to add to the invalidated region without triggering a redraw loop but would update the full items area?
Another thought is I can just use the full window RECT size and use a right margin large enough that wouldn't be under the scroll area but I'd rather not do that.
Thanks!
Related
I am trying to create app. In the form, there is only 3 button in a groupbox. I want to make the groupbox always fit in the screen. The problem is when i minimize the form, there is vertical and horizontal scroll. So i cannot see the whole groupbox border:
I want to make the groupbox to minimize without the scroll and i am able to see all the border just like when in the maximize screen as below:
I have already tried groupbox autosize to true while anchor to top, bottom, right, and left but it is still not working. Any idea how i can achieve this?
As #ib11 said you need to go to Dock and select Fill. In addition, if you want to make your group box not fill the form but grow with it, you'll probably need to change the Anchor to all sides. That's why your previous settings didn't work because anchor doesn't fill the screen, it's just a property to grow with the screen. Fill makes it possible so that you can have a group box or any other control always fill the screen.
See this image for dock:
See this image for anchor:
You need to set the Dock property of the GroupBox to Fill.
Like so:
I'm faced with a problem where I need to display some characters in a tree-view item (those belonging to the Symbol charset) using Symbol font while others in the default System font (Segoi UI on my Windows 7).
Custom draw allows us to draw different items using different fonts, but I would like to draw the same item string using different fonts as it applies to each character in the string as told above.
So, what I've done with not-so-pleasing results w.r.t. drawing performance upon a horizontal scroll when the number of items is more so far is this:
I disabled horizontal scrolling in my tree-view control using TVS_NOHSCROLL style (since I'm using my own scroll bar control inside the tree-view window to handle all horizontal scrolling)
I sub-classed the treeview control and in the sub-classed winproc, I handle the horizontal scroll notification and mouse notification (where I do my own hittesting and send message like TVM_EXPAND and TVM_SELECT as a result of mosue clicks/double-clicks). Also the scroll bar range is set based on how wide my custom drawn string is (the maximum length amongst all items).
I draw the string for each item upon receiving CDDS_ITEMPOSTPAINT using my own fonts for each character in the item.
The above approach (I left out some details for the sake of brevity) works BUT there are some problems which makes me post this question here and look for an alternare way:
Problems:
The horizontal scroll bar control I create is hosted "inside" the tree-view control at the bottom of the tree-view window. However, when the number of items goes beyond what the tree-view client area can accommodate vertically, the last visible tree-view item gets obscured by the scroll bar control. This can be solved by not making the scroll bar a child of the tree-view and hosting it outside the tree-view window just below it. But I don't want to do this since the scroll bar should typically be a child window of the tree-view.
This is the major one. Since I draw the items myself at each horizontal scroll, the drawing performance upon horizontal scrolling is very slow and also leads to flicker upon scrolling.
Any ideas will be much appreciated as I've been grappling with this for the last one week without success.
I can also post the relevant code here if you want to see the approach I took but I'm sure there shoould be a better approach to this and there must be some other people who would've faced this problem and solved it in the past.
Thanks in advance.
Custom-draw allows you to draw items however you want. You are not limited to a single font per item. When you receive the NM_CUSTOMDRAW notification, draw whatever you want on the provided HDC for the specified item. You can draw pieces of text in one font, pieces of text in a different font, etc. Be sure to return CDRF_SKIPDEFAULT so the TreeView itself will not try to draw anything on the item.
#Anurag S Sharma: I tried to edit this into Remy's answer. It's incomplete as is, but addresses your comment/concerns and answers this particularly vexing/useful question...
The problem is that ff I return CDRF_SKIPDEFAULT, Windows does not even draw the +/- buttons (expanding/collapsing) nor the indent lines in the control which I do want Windows to draw. – Anurag S Sharma
To retain the lines, buttons, and icons you can use ExcludeClipRect to mask only the text region and instead of returning CDRF_SKIPDEFAULT, return 0 as if you didn't draw anything. This itself would not be necessary if the text of the tree item was empty, except that the margins of the text will always be drawn by the default handler (note that Microsoft's controls do not always respect clipping shapes, but in this case they do.)
To replicate the classic TreeView label style in your custom draw procedure you need to do something like the following:
HTREEITEM item = (HTREEITEM)p->dwItemSpec;
TreeView_GetItemRect(p->hdr.hwndFrom,item,&p->rc,1);
RECT cr, rc = p->rc; GetClientRect(p->hdr.hwndFrom,&cr);
DrawTextW(p->hdc,text,-1,&rc,DT_CALCRECT|DT_NOPREFIX|DT_NOCLIP);
rc.right+=4; rc.bottom+=2; IntersectRect(&rc,&cr,&rc);
ExtTextOutW(p->hdc,rc.left+2,rc.top+1,ETO_CLIPPED|ETO_OPAQUE,&rc,text,wcslen(text),0);
I have an MFC app that embeds a Scintilla text edit control. I want to customize the Scintilla control to display some custom controls next to the vertical scrollbar. Essentially, I want to render some controls in the orange area below, where the green area represent the scroll bars:
I tried overriding the WM_NCCALCSIZE message of the Scintilla window and subtracting an offset from the right side of the client rectangle. Here is the code:
void CScintillaCtrl::OnNcCalcSize(BOOL bCalcValidRects, NCCALCSIZE_PARAMS* lpncsp)
{
CWnd::OnNcCalcSize(bCalcValidRects, lpncsp);
lpncsp->rgrc[0].right -= 100;
}
However, this causes the vertical and horizontal scroll bars to reposition themselves to account for the smaller client width, as shown below:
I'm not sure if this behavior is caused by Scintilla or Windows. Is there a way I can adjust the client area and preserve the positions of the scroll bars?
I found a Scintilla specific solution. I can use the SCI_SETMARGINRIGHT command to add a margin to the right side of the client area, and then render my controls inside that.
How to implement a scroller to one of the labels before reaching the top of the screen has remained at the top, and the text scrolls from another label beyond the limits of the screen, such as in instagramm, except instead of photos text from the second label
Scroll View
scroller to one of the labels before reaching the top of the screen has remained at the top, and the text scrolls from another label beyond the limits of the screen,
http://www.youtube.com/watch?v=mws6Zbq_y6c
Darwich
i need to put a horizontal scrollbar in a dynamically created Hbox. im writting the code like this:
hbxWallAImg = new HBox();
hbxWallAImg.horizontalScrollPolicy="on";
but still the no scrollbar is comming.
i have tried by setStyle also. but it is also not working.
The scroll bar will not be visible unless the content of the box doesn't fit in the box's view port. So just by setting the scroll policy, it won't be displayed, but rather when the element will "know" that in case its content doesn't fit, it should display scroll bars. You also need to add some children and dimensions (with, height) to the HBox.
Without dimensions, it will "stretch" as much as it needs to accommodate the content, so no scroll bars will be visible in this case also.
You can find all the info about view ports and scrolling in Flex 4 here: http://www.adobe.com/devnet/flex/articles/flex4_viewport_scrolling.html
Hope this helps.
Have a good day,
Romi