CompositeInformationControl replaces the original shell of its AbstractInformationControls

[markdomeng]

at CompositeInformationControl : 111 (control.setParent(parent))
effectively replacing the original fShell of the AbstractInformationControl

this causes unexpected behaviors to its consumers.
Some consumers I found while working on some LSP project (we are using GenericEditor):

• MarkerInformationControl

  • at line 163, computeSizeHint() : this returns a very small Point(2,2) because the child controls are stolen. (Only if it is created by CompositeInformationControlCreator at line 123 as a CompositeInformationControl)

  • at line 149, setInput() : the shell is not getting disposed after applying the quickfix

• BrowserInformationControl

  • at line 225, createContent() : I only observed this when using dark mode, but the background color of the BrowserInformationControl is different from the MarkerInformationControl when they are created as a CompositeInformationControl. I suspect this is the cause

(I am not able to reproduce it in a regular eclipse, everything mentioned above were only observed in our project)

Tested under this environment:

• OS & version: Windows 11
• Eclipse IDE/Platform version (as shown in Help > About):
  • Version: 2024-06 (4.32)
  • Build Id: I20240601-0610

Community

• I understand reporting an issue to this OSS project does not mandate anyone to fix it. Other contributors may consider the issue, or not, at their own convenience. The most efficient way to get it fixed is that I fix it myself and contribute it back as a good quality patch to the project.

[markdomeng]

proposed fix: markdomeng@dcd65ae

but this may cause issues to child classes relying on the getShell() to do something to its child controls, because it will now return a shell that contains controls other than the one it created .

example scenario:
if CompositeInformationControl creates MarkerInformationControl and BrowserInformationControl,
getShell() will now contain all controls created by both MarkerInformationControl and BrowserInformationControl

so in order to fix this, child classes of AbstractInformationControls should not rely on getShell() to access its child controls.
I propose we also provide accessors to fContentComposite, and fStatusComposite, as an AbstractInformationControl will always have these 2

sample use case:
in MarkerInformationControl : computeSizeHint()
instead of getShell().getSize() we could return the size of the content + the size of the status composite as the actual size