Update holograms on PlotChangeOwnerEvent in correct way

[BlockyTheDev]

Overview

Fixes #43

Description

This fixes a bug, where new holograms where created on PlotChangeOwnerEvent, but the old one wasn't removed. Because of that there was a huge stack of armorstands and unreadable text created over the time. With this pull request it is going to be deleted first and then the a new one ist created.

Submitter Checklist

• Make sure you are opening from a topic branch (/feature/fix/docs/ branch (right side)) and not your main branch.
• Ensure that the pull request title represents the desired changelog entry.
• New public fields and methods are annotated with @since TODO.
• I read and followed the contribution guidelines.

[SirYwell]

I'd assume this call

HoloPlots/src/main/java/com/plotsquared/holoplots/PSHoloUtil.java

Line 115 in 127dc89

hologram.clearLines();

to already prevent the issue from happening in the first place, do you know why that isn't the case?

[BlockyTheDev]

Ohh, I should have looked into the method updatePlayer. As far as I see it should handle the "replacement" of the lines, which is not working right, too.

Sorry for my English. I am a German student.

[BlockyTheDev]

I found out why the updatePlayer methode isn't working in the way it should. I will investigate that when I have time in the next days.

Edit: It is not working, because in this line the plot has a new owner, so the hash in the HoloPlotID instance is a different one, in comparison to the stored hologram in the HashMap.

HoloPlots/src/main/java/com/plotsquared/holoplots/PSHoloUtil.java

Line 91 in 127dc89

HoloPlotID id = new HoloPlotID(plot.getId(), plot.getOwnerAbs());

Because of that it is entering following if statement block:

HoloPlots/src/main/java/com/plotsquared/holoplots/PSHoloUtil.java

Line 94 in 127dc89

if (!holograms.containsKey(id)) {

The options I am seeing to fix this, is (1) adding an UUID argument with the old player to the updatePlayer methode, which gets the result of e.getOldPlayer() on the call in onPlotChangeOwner and in the other calls from the other subscribed events null or (2) removing the hologram in onPlotChangeOwner (without missing to remove it from the HashMap) and then calling the updatePlayer methode again.

If it would be my plugin i would solve it in the second way. @SirYwell just write me the way I should use (If there is a better one just write too) then I am going to make a new commit in this pr tomorrow.

[SirYwell]

Edit: It is not working, because in this line the plot has a new owner, so the hash in the HoloPlotID instance is a different one, in comparison to the stored hologram in the HashMap.

Good catch, that makes sense. I think your second suggestion makes sense, but there should be a comment in the code explaining it briefly.

[BlockyTheDev]

Now it is removing the HoloPlotID key completely from the HashMap. I also added an information comment, why this way is selected.

[SirYwell]

One minor nitpick, but looks good otherwise.

[SirYwell]

Looks good, thanks.

[PierreSchwang]

Looks reasonable