From dd4c90fc680a8e9b1d3d4075a5ca8c8b683fe253 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kim=20Silkeb=C3=A6kken?= <kim.silkebaekken@gmail.com>
Date: Thu, 13 Dec 2012 13:16:09 +0100
Subject: [PATCH] Cache and retrieve segment contents for non-current vim
 windows

This resolves the issue with non-current windows using the contents of
the currently selected window.
---
 examples/vim/powerline.vim    |  2 +-
 powerline/ext/vim/renderer.py | 22 ++++++++++++++++++----
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/examples/vim/powerline.vim b/examples/vim/powerline.vim
index 33bba76a..093636e1 100644
--- a/examples/vim/powerline.vim
+++ b/examples/vim/powerline.vim
@@ -22,7 +22,7 @@ endfunction
 
 function! s:WinDoPowerline()
 	if ! exists('w:powerline')
-		let w:powerline = ''
+		let w:powerline = {}
 	endif
 
 	let &l:stl = '%!Powerline('. winnr() .')'
diff --git a/powerline/ext/vim/renderer.py b/powerline/ext/vim/renderer.py
index 59dcadef..19ee4d59 100644
--- a/powerline/ext/vim/renderer.py
+++ b/powerline/ext/vim/renderer.py
@@ -21,14 +21,28 @@ class VimRenderer(Renderer):
 		self.hl_groups = {}
 
 	def render(self, winnr):
+		'''Render all segments.
+
+		This method handles replacing of the percent placeholder for vim
+		statuslines, and it caches segment contents which are retrieved and
+		used in non-current windows.
+		'''
 		current = vim_getwinvar(winnr, 'current')
 		winwidth = vim_winwidth(winnr)
 
-		mode = vim_mode()
-		if not current:
-			mode = 'nc'
+		if current or not vim_getwinvar(winnr, 'powerline'):
+			contents_cached = {segment['key']: segment['contents'] for segment in self.segments if segment['type'] == 'function'}
+			vim_setwinvar(winnr, 'powerline', contents_cached)
 
-		statusline = super(VimRenderer, self).render(mode, winwidth)
+		if current:
+			mode = vim_mode()
+			contents_override = None
+		else:
+			mode = 'nc'
+			contents_cached = vim_getwinvar(winnr, 'powerline')
+			contents_override = {k: contents_cached[k].decode('utf-8') for k in contents_cached.keys()}
+
+		statusline = super(VimRenderer, self).render(mode, winwidth, contents_override)
 		statusline = statusline.replace(self.PERCENT_PLACEHOLDER, '%%')
 
 		return statusline