Is there a WM_MEASUREITEM type item for custom drawing treeview items via NM_CUSTOMDRAW? I'd like to be able to report the width the item will actually be once I paint it in the post paint so a horizontal scrollbar doesn't show up when not needed (because I truncate the text with a ...).
Thanks.
AFAIK, there is no equivalent of WM_MEASUREITEM for a TreeView control.
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I am trying to make a NSSearchField taking up the whole width of a toolbar in a NSWindowController.
I created a new NSWindowController using Xcode storyboard, add a toolbar to it, when add search field to the toolbar.
I drag the search field from allowed toolbar items to default toolbar items
Set toolbar item's max width to a large number say 1000
I build the app and run. The search field shrinks when window width shrinks, but does not expand beyond a certain width when window width expands.
The question is how to make search field expand and take up all remaining space of the toolbar?
It doesn't sound to me like the toolbar is really what you want to use here. The purpose of the toolbar is to allow multiple UI elements to be included in a user-configurable way. If you want to force one element that takes up the entire width, I suggest just putting it in the window's content view and setting up the layout constraints to pin to both the left and right sides. If you set the "Textured" check box in Interface Builder, it should look roughly the same as it would have looked using the toolbar.
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 use listbox.ScrollIntoView(item), but as long as this item is in listbox view, it won't scroll.
Actually I want the item to be centered in the listbox's view. Is there anyway to do this?
Unfortunately this is not all that easy, it depends on whether your listbox is virtualized or not, which depends on the panel that it uses to render its contents. For a non-virtualizing listbox, you can set the vertical scroll position by invoking the following method on the ScrollViewer which is part of the listbox template, where offset is in pixels.
ScrollViewer.ScrollToVerticalOffset(offset);
For virtualizing, you can invoke the following method on the VirtualizingStackPanel, where offset is the list location (you can use a double value, i.e. scrolling to 3.5 will scroll to half way between index 3 and 4):
ItemsHostStackPanel.SetVerticalOffset(offset);
For how to use this code in context, look at the jump list control I implemented here:
http://wp7contrib.codeplex.com/SourceControl/changeset/view/72741#1502048
I have listbox in WP7 where i need to scroll to certain items according to user choice and i use scrolltoview for that. Problem is that i need listbox to scroll listbox enough so that selected item appears aligned to top edge. Right now scrolled item is positioned at bottom.
Assuming that you have fixed (and known) size items and a fixed (and known) size of listbox, can't you just account for the number of items between the top and bottom of the visible space and adjust your offset accordingly?
Unfortunately Matt solution was unusable in this case because listbox items were too big taking almost whole screen per item. But i was able to solve this problem by getting scrollviewer of listbox and use its scroll method to scroll into listbox SelectedIndex. Item is still not positioned perfectly after scrolling but height difference is minimal and acceptable for me.
So I'm using the method:
[someWindow setContentBorderThickness:24.0 forEdge:NSMaxYEdge];
But I can't seem to get the toolbar to increase in height. It simply stays the same as in default. Can anyone shed some light here?
An NSToolbar is automatically resized to accommodate the height of the tallest NSToolbarItem. The standard (large) toolbar items are all 32 px tall, so the toolbar has no need to make itself larger. If you do something like add a custom view toolbar item, then it will be resized to accommodate that item, as shown in the image below:
(To accomplish the result shown above, I clicked on the toolbar twice in IB to bring down the Allowed Toolbar Items sheet, then dragged an NSView custom view from the library palette onto that sheet).
P.S. I'd recommend using this capability with discretion.
You cannot specify an arbitrary height for NSToolbar. You can, however, specify a size mode. A toolbar with 24x24-pixel icons has a small size mode:
[toolbar setSizeMode: NSToolbarSizeModeSmall];
which is equivalent to Size: Small in Interface Builder’s Attributes Inspector.