Yesterday, I pushed my initial import of a Google Chrome-like tab control for WPF to a new GitHub repo. I have it rendering the look of the tabs and some very rudimentary dragging of the tabs. I don’t like the implementation of the dragging, yet, so I’ll have to fix that.
I’ve released it under my favorite FOSS license, the MIT license. Feel free to make a million dollars off of it, use it in your commercial software, or whatever. However, if you do make a million dollars off of it, please send a little my way. Help support FOSS.
(This project’s for you, eb² and DrH. :)
The implementation
Right now, the functionality for this custom tab control lives in three coöperating classes.
ChromiumTabControl
: This is the tab control class that users would put in their XAML. Like the
.NET TabControl, it inherits from Selector found in the
System.Windows.Controls.Primitives namespace. It maintains the
SelectedContent shown by the tab control, provides the default
look-and-feel as found in Themes\Generic.xaml, and manages the z-index of
the children so that the selected tab appears on top and the overlap of tabs
appear in reverse order of their position in the tab control’s child list.
ChromiumTabPanel : This custom layout panel provides the layout logic for the tabs at the top of the control. Right now, it merely makes each tab 100 pixels wide and draws the line along the bottom of the tabs. I believe that, as this project matures, it will become responsible for handling tab movement and coördinate with the ChromiumTabControl to reorder children on drag complete.
ChromiumTabItem
: This provides the wrapper for children foudn in the ChromiumTabControl.
Like the TabItem found in System.Windows.Controls, it inherits from
HeaderedContentControl. Its default representation, as found in the
Themes\Generic.xaml file, represents itself as just the tab contained by
the ChromiumTabPanel. Right now, it initiates and tracks the mouse
movement, but as I alluded to in the description of ChromiumTabPanel, that
specific responsibility will move out of this class. It resuses the
Selector.IsSelected dependency property to mark its selection in the tab
control.
To get this far, I used the excellent
WPF: TabControl Series
as a starting point and, then, the decompiled IL from the
PresentationFramework assembly that comes with WPF. I didn’t imagine the
amount of internal plumbing found in the TabControl and its associated
classes that Microsoft decided to keep internal to the WPF assembly. It
disappointed me, somewhat, because that functionality would have made my life
a lot easier and I could not understand why they decided to not expose it.
Want to help?
If so, then follow these easy steps.
- Download and install Google Chrome (if you haven’t already).
- Run Google Chrome. Play a lot with the tabs to get their behavior firmly in your mind.
- Fork the wpfchrometabs repository and make changes that implement some of the behavior that you see in Google Chrome that does not yet exist in wpfchrometabs.
- Gerneate a pull request.
Make small changes that address a specific part of the Google Chrome interface behavior. I’ll ignore “big” pull requests. :)