Multi-selection in TreeTable doesn't work

[Nyan11]

Hello,

Description

I encounter a bug while using SpTreeTablePresenter where the selection was not the same on the model and visually.

Examples:

SpTreeTablePresenter new
		  beMultipleSelection;
		  expandRoots;
		  addColumn: (SpCompositeTableColumn new
				   title: 'Classes';
				   addColumn: (SpImageTableColumn new
						    evaluated: [ :aClass |
							    self iconNamed: aClass systemIconName ];
						    width: 20);
				   addColumn: (SpStringTableColumn evaluated: #name);
				   yourself);
		  roots: { Object };
		  children: [ :aClass | aClass subclasses ];
		  whenSelectionChangedDo: [ :new | Transcript crShow: new selectedItems printString ];
		  open

1. I click on Object -> The transcript show: {Object}
2. I press shift
3. I click on Stream -> The transcript show: {Stream. Object. Exception. Path}
4. I release shift
5. I click on Exception -> The trascript should show {Exception}, but it doesn't.

Possible fix

I think the bug come from the method: #basicSelectionChanged: in the class: SpMorphicTreeTableAdapter

basicSelectionChanged: ann

| selection |

	selection := self presenter selection.
	ann newSelectedIndexes ifEmpty: [ ^ selection unselectAll ].
	(ann newSelectedIndexes difference: ann oldSelectedIndexes) ifEmpty: [ ^ self ].

	selection selectPaths: (ann newSelectedIndexes
		collect: [ :index | self widget dataSource pathFromIndex: index ]).

	self presenter isActiveOnSingleClick ifTrue: [
		self presenter doActivateAtPath: selection selectedPath ]

The method #difference: (line 7) return an empty collection in the example above. The line 7 should check if the new selection is different. In the example they are, but the command differnce: return an empty collection.

I suggest this solution, where we check the difference of new and old selection and the difference of old and new selection after. \ = difference:, | = union:.

basicSelectionChanged: ann

	| selection |
	selection := self presenter selection.
	ann newSelectedIndexes ifEmpty: [ ^ selection unselectAll ].
	(ann newSelectedIndexes \ ann oldSelectedIndexes) | (ann oldSelectedIndexes \ ann newSelectedIndexes) ifEmpty: [
		^ self ].

	selection selectPaths: (ann newSelectedIndexes collect: [ :index |
			 self widget dataSource pathFromIndex: index ]).

	self presenter isActiveOnSingleClick ifTrue: [
		self presenter doActivateAtPath: selection selectedPath ]

The method difference is also present in other SPEC class. Maybe this bug is present in them too:

• SpMorphicTableAdapter >> #selectionChanged:
• SpAbstractMorphicListAdapter >> #selectionChanged:
• SpMorphicComponentListAdapter >> #selectionChanged:
• SkSpMorphicSeekerTableAdapter >> #selectionChanged:

Other

Pharo 11.0.0 Build information: Pharo-11.0.0+build.700.sha.53659ed8c20ddb4b644a58135325ff84be4e063e (64 Bit)

I used the Spec package directly present in Pharo image.