I'm referring to the comment by underscore_d given in the context of this question Gtk ComboBox width based on contents:
If you [...] change [the model of a combobox to a new one] with all shorter options... [the combobox] doesn't
shrink back down.
I've noticed that myself, and I've tried to shrink the combobox with
gtk_widget_queue_draw (combobox);
while (gtk_events_pending ()) {
gtk_main_iteration ();
}
but to no avail; other "tricks" like using gdk_threads_add_idle didn't work either.
So there is no way, either by code or by any setting, to shrink an overly wide combobox?
I destroy now the combo box widget and recreate it every time; the size change is quite big and the combo box looks really bulky if I don't do this. Not very elegant, but so be it.
Related
I need to develop a simple WPF application. In the UI window, There are Labels and Text Blocks towards the left and Buttons towards the right.
Figure 1
Based on a config setting (whether the user is left-handed or right-handed) I need to switch the controls, Buttons towards the left and Labels and Text Blocks towards the right.
Figure 2
Can you please recommend a good way to address this requirement?
Depends what the scope of the app is likely to be.
2 alternatives:
1)
I think it likely as an app grows that there will be more than just buttons.
I would probably build a usercontrol which encapsulates this behaviour for a label and control. The usercontrol uses a static to decide where the textblocks are positioned but would look something like the row edit control in this:
https://gallery.technet.microsoft.com/WPF-Entity-Framework-MVVM-78cdc204
Which is a usercontrol has a contentpresenter in it so you can put any control you like ( such as a button ) "in" it and set a dependency property for the label.
2)
Define 2 contentcontrol templates similar to the one used in this:
https://social.technet.microsoft.com/wiki/contents/articles/28597.aspx
Put them in separate resource dictionaries and give them the same key.
Merge into application.current.resources the appropriate resource dictionary and hence style.
Seeing as this is an app setting, this is presumably a start up thing. People don't just change their "handedness" dynamically. So you could probably use these as staticresource. If they're realistically going to change at run time then I think this would be a bit more involved because you'd need to force re render of a view.
2 Templates are probably the right and stylish solution here as #RajN said.
Also you can define a grid with 2 columns and switch the property 'Grid.Column' of each controls accordingly
Maybe not the best way, but I managed to achieve this using a grid as per your suggestions. Thank you all for your valuable feedback.
I switched the columns and changed the widths accordingly.
if (AppSettings.IsLeft)
{
parentGrid.ColumnDefinitions[0].Width = new GridLength(400, GridUnitType.Pixel);
parentGrid.ColumnDefinitions[1].Width = new GridLength(1, GridUnitType.Star);
Grid.SetColumn(buttonGrid,0);
Grid.SetRow(buttonGrid,0);
Grid.SetColumn(contentGrid,1);
Grid.SetRow(contentGrid,0);
}
I have a strange problem with a listbox. I added only the listbox and a button which adds items to the listbox. If I click an item in the listbox it seems to have some strange multi selection mode on or something... i recorded a short screen cast, see for your self:
http://www.youtube.com/watch?v=zV4424ipNEA
any ideas whats wrong?
That is a known issue, as all those strings are the same the selection gets confused because they all are essentially the same object. If you create two identical strings in .NET it does not necessarily create a new one but may reuse the first instance, i am not an expert on this though.
Either wrap the strings in a class (make them the Content of a ListBoxItem for example) or make sure the values are unique.
As you know, the built-in themes all define styles for the standard controls such as the TreeView control. We're trying to create something that looks an awful lot like a TreeView but isn't actually one, nor is it a subclass of one. It just has parts that we want to look like one for consistency.
For instance, our control too has a selected item whose background we'd love to match to the appearance of the background for the selected item in a TreeView (or more accurately the TreeViewItem) for the current theme. (You can't simply use highlight color as the themes have nice gradient brushes and borders, not just a solid brush.) Same with our expand/collapse togglebuttons. We want them to look just like the ones used in a TreeView for the current theme. (i.e. Sometimes a triangle, sometimes a box with a '+' in it, etc.)
Now while we can simply rip open Expression and copy the styles ourselves (or at least the parts that we need), we'd have to do that for each and every theme that MS provides. Plus, that wouldn't handle newer themes. And in a purest standpoint, that's duplicate styling information which just sits wrong with me.
Also, if someone styles the actual TreeView(Item), we want to pick it up as well. Since the parts that we want to style are required parts of a TreeView, we feel pretty confident that they're in there somewhere style-wise.
Not even sure what I want to do is possible but if anyone knows, they're most likely here on SO!
Yet another question close to a month old without even a comment. Very odd for the SO community to not chime in at least once! Guess it's not possible.
Well, what we ended up doing was using 'Show Me The Template' (Google it) to get the templates for the part (we don't have Expression), then manually managing them ourselves instead of using the built-in styles. NOT at all what we wanted to do since we don't know of a way to get the nice gradients that are defined in the system already without duplicating them, but the end result does match perfectly so there's that. As such, this too is getting marked as the answer. I'll gladly change it if someone else actually gives me one that works (or is close enough! Just need something people! Feel like I'm posting in a vacuum here!
Please refer this control
http://www.charlespetzold.com/blog/2009/10/Using-Text-Outlines-in-Silverlight.html
The formattedtext control is a shape which helps to generate the shape of the text with proper geometry. I would like to make this control act like a text box with cursors and features like typing in from keyboard.
Right now I use an invisible text box with a formattedtext control to act like that. But the cursor position always creates a problem when the size of the text is not equal to the size of the rendered text as shape.
Can anyone please show the way to achieve this.
Well, I built a syntax highlighting textbox using the method you describes.
Actually, at first I wanted to rebuilt everything too, but I thought : I have to build the caret fonctionnalities, the selection brush, manage a lot of different events, like selection with mouse or keyboard, deletion, Copy/Cut/Paste, etc etc...
That's a LOT of work, and windows users are used to select text in textboxes for instance, so this complex implementation cannot be left unimplemented. We must follow some Microsoft guidance on how a textbox must feel.
Actually, I think that building a new textbox from scratch is not the way to go. I suggest you to continue on your current method. If you have different fonts in the same textbox, use a RichTextBox, and handle the font changes in the textbox as well as in the formatted text.
Also, a good think to implement is to only draw the visible text with the formattedtext (but only if the user can write several hundreds of text lines).
What would be a good approach to display and edit large amount of unformatted text (just like notepade does) using WPF? Loading a big string into a TextBox makes the UI unresponsive. The overall performance is not nearly comparable with TextBox Controls of previous Microsoft UI Frameworks.
What options do I have to solve this problem. I do not want to block the UI thread while the text control loads the text. Also I might need some sort of "virtualization" because it might not be a good idea to load the whole text into the control (I guess that 20MB of text would create a lot of glyphs even if they are not visible). It seems that TextBox doesn't even have an AppenText() Method anymore so I don't even have a way to control asynchronous loading of the text.
Isn't this a common problem? It seems that WPF does not provide anything for this out of the box. Why is this so?
AvalonEdit, the text editor in SharpDevelop, was written completely from scratch in WPF and is optimized for large amounts of text. It doesn't support rich text (although it does support syntax highlighting and other cool features such as folding). I think this might fit your bill perfectly.
Here is an article on the editor written by the developer:
http://www.codeproject.com/KB/edit/AvalonEdit.aspx
I am not sure if this helps, but have you tried using FlowDocumentPageViewer and FlowDocumentReader?
It also has very good annotations support and looks ideal for loading documents in text format.
The problem is that the TextBox is a single container element. List controls, such as ListBox virtualize very well because of container recycling. There really isn't anything simple that you can do to speed up the TextBox.
But the TextBox control does have an AppendText() method:
TextBox tb = new TextBox();
tb.AppendText("Hello");
So yes, you can use this to dynamicly add some text just like you mentioned.
You can just use a textbox with a style that gives the user more room to view the text. There are probably more advanced controls from Telerik and others but if you don't require editing options that should suffice.
You could always mix and match technologies: you could drop a WinForms TextBox onto a WPF parent. You lose things like styling, opacity, animation, transforms, etc., but if all that matters is editing text, the WinForms TextBox does that just fine.
Have you tried the WPF RichTextBox? You'll definitely want to read up on the FlowDocument information if you go this route.
You could use FlowDocument, but this doesn't work out of the box to bind to the Document property of a FlowDocument in MVVM.
Another solution is using FlowDocumentScrollViewer and bind to its Document property.
(or you could even use a FlowDocumentReader and bind its Document property, similar to the FlowDocumentScrollViewer. This gives you a different UI.)
The View:
<FlowDocumentScrollViewer Document="{Binding FlowDocument, Mode=OneWay}" />
The ViewModel:
FlowDocument fd = new FlowDocument();
Paragraph p = new Paragraph();
Run r = new Run();
r.Text = "large text";
p.Inlines.Add(r);
fd.Blocks.Add(p);
FlowDocument = fd;
private FlowDocument _FlowDocument;
public FlowDocument FlowDocument
{
get{ return _FlowDocument; }
set
{
_FlowDocument = value;
NotifyOfPropertyChange(nameof(FlowDocument));
}
}
see also this for extra performance tips: https://learn.microsoft.com/en-us/dotnet/framework/wpf/advanced/optimizing-performance-text#flowdocument-textblock-and-label-controls
How about trying something like this:
Keep the whole string in memory but show only a 'slice' of it in the textbox. Size of the that sliced string would be dynamically calculated depending on the size of textbox, font size etc.
Of course this involves a lot of not trivial code for proper displaying, synchronizing and so on, but it seems the way to go.
One other option is to use Scintilla.NET. It has the best performance for large amounts of texts I have seen so far. Loading large files is almost instantaneous. Even though it is a WinForms control, you can embed it into your WPF window with WindowsFormsHost container. There is syntax highlighting and some other features that should be more than enough for displaying unformatted text. From the downsides - since this is a WinForms control, it overlaps other WPF UI elements. Also there may be issues with resizing the control. Unfortunately, I don't see any better option than using a non-WPF control instead of the default TextBox and RichTextBox.