Bug 477779

Summary:	Provide default methods for IContentProvider
Product:	[Eclipse Project] Platform	Reporter:	Lars Vogel <Lars.Vogel>
Component:	UI	Assignee:	Lars Vogel <Lars.Vogel>
Status:	RESOLVED FIXED	QA Contact:
Severity:	enhancement
Priority:	P3	CC:	alex.blewitt, brian.vosburgh, bsd, daniel_megert, Lars.Vogel, markus.kell.r, simon.scholz, sxenos, tom.schindl
Version:	4.6	Keywords:	noteworthy
Target Milestone:	4.6 M6
Hardware:	PC
OS:	Linux
See Also:	https://git.eclipse.org/r/56214 https://git.eclipse.org/c/platform/eclipse.platform.ui.git/commit/?id=62372d7c5cb099ed3286d3fa138c186eb42cbf2d
Whiteboard:
Bug Depends on:	477774
Bug Blocks:	477782

Description Lars Vogel

2015-09-18 05:05:50 EDT

Java 8 allows to provide default methods, we should provide empty default methods for inputChanged and dispose in IContentProvider.

Comment 1 Eclipse Genie

2015-09-18 05:14:14 EDT

New Gerrit change created: https://git.eclipse.org/r/56214

Comment 2 Eclipse Genie

2016-02-16 02:36:30 EST

Gerrit change https://git.eclipse.org/r/56214 was merged to [master].
Commit: http://git.eclipse.org/c/platform/eclipse.platform.ui.git/commit/?id=62372d7c5cb099ed3286d3fa138c186eb42cbf2d

Comment 3 Brian Vosburgh

2016-02-26 12:16:51 EST

Just in case you did not know: Defining a default implementation for an interface is not completely harmless. :-)

This change caused a compile error in Dali (bug 488427). This is because Dali has an interface (StructuredStateProvider) that indirectly extends IContentProvider
and IBaseLabelProvider; and IBaseLabelProvider also defines a dispose() method. The compile error reads like this:

The default method dispose() inherited from IContentProvider conflicts with another method inherited from IBaseLabelProvider

The "fix" was to define a default implementation of dispose() in StructuredStateProvider.

Comment 4 Thomas Schindl

2021-04-19 04:36:13 EDT

Well I just ran into this as well and I have to say the abuse of "default" methods is completely inappropriate. They have been invented so provide new features and not to implement convenient APIs.

A problem i see in our code base now is that people are implementing an interface are not forced to implement the dispose-method because this default-implementation hides it from them.

I know this ship has sailed a long time ago but I think adding default-methods just to provide convenience methods needs to be discussed