Eliminate unnecessary CPU usage

[chendo]

KSImageNamed normally hooks into textViewShouldChangeTextInRange:replacementString:, which causes a lot of KSImageNamed methods to be hit every time the text view changes.

Here is a paste of Obj-C message sends matching KSImageNamed when I press Return only once on an empty line: https://gist.github.com/chendo/7130668

After poking around in DVTTextCompletionController+KSImageNamed and looking at the trace, it seems that replacementString is never nil (at least in Xcode 5.0.1), which is causing imageCompletions to be enumerated every single time text changes.

This would be particularly bad in a project with many image assets.

This PR removes the textView swizzle and hooks into DVTTextCompletionListWindow's showInfoPaneForCompletionItem: and _hideWindow methods, so KSImageNamed is only run when necessary.

Below is the remaining Obj-C message sends matching KSImageNamed when pressing Return once on an empty line after applying this PR:

-> -[DVTTextCompletionController(KSImageNamed) swizzle_acceptCurrentCompletion]
<- -[DVTTextCompletionController(KSImageNamed) swizzle_acceptCurrentCompletion]
-> -[DVTSourceTextView(KSImageNamedSwizzle) swizzle_shouldAutoCompleteAtLocation:]
    -> +[KSImageNamed sharedPlugin]
    <- +[KSImageNamed sharedPlugin]
    -> -[KSImageNamed completionStringsForType:]
    <- -[KSImageNamed completionStringsForType:]
<- -[DVTSourceTextView(KSImageNamedSwizzle) swizzle_shouldAutoCompleteAtLocation:]
-> -[DVTSourceTextView(KSImageNamedSwizzle) swizzle_shouldAutoCompleteAtLocation:]
    -> +[KSImageNamed sharedPlugin]
    <- +[KSImageNamed sharedPlugin]
    -> -[KSImageNamed completionStringsForType:]
    <- -[KSImageNamed completionStringsForType:]
<- -[DVTSourceTextView(KSImageNamedSwizzle) swizzle_shouldAutoCompleteAtLocation:]

I've only tested this on Xcode 5.0.1.

[chendo]

A side effect of this PR is it also fixes compatibility issues with chendo/FuzzyAutocomplete as FuzzyAutocomplete disables the replacementString option as it does not make sense when using fuzzy matching.

[ksuther]

Thanks, this looks good! I'll run it for a couple of days and merge it in, assuming it continues to work as it seems to be right now.

[chendo]

Sounds good to me! I don't work with imageNamed: that much so I haven't really put it through its paces (I've got a grand total of 6 images in a personal iOS app I'm working on).

[ksuther]

Well I fixed another bug and beat on this a bit, so I'm merging it now. Thanks again!

[chendo]

Awesome :D Thanks for the plugin!