From a5d2fac9f18f121f3bd5fb3c256a227da8d8099c Mon Sep 17 00:00:00 2001
From: YUKI Hiroshi <shimoda@clear-code.com>
Date: Tue, 13 Sep 2016 12:42:34 +0900
Subject: [PATCH] Allow to disable "shrink others while dragging" feature

---
 content/treestyletab/res/tabsDragUtils.js | 15 +++++++++++----
 defaults/preferences/treestyletab.js      |  5 +++++
 modules/tabbarDNDObserver.js              |  4 +++-
 3 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/content/treestyletab/res/tabsDragUtils.js b/content/treestyletab/res/tabsDragUtils.js
index 2e2f4722..d35a08db 100644
--- a/content/treestyletab/res/tabsDragUtils.js
+++ b/content/treestyletab/res/tabsDragUtils.js
@@ -5,7 +5,9 @@
    window['piro.sakura.ne.jp'].tabsDragUtils.initTabBrowser(gBrowser);
 
    // in dragstart event listener
-   window['piro.sakura.ne.jp'].tabsDragUtils.startTabsDrag(aEvent, aArrayOfTabs);
+   window['piro.sakura.ne.jp'].tabsDragUtils.startTabsDrag(aEvent, aArrayOfTabs, {
+     shrinkOthers : true // shrink other dragged tabs while dragging
+   });
 
  This Source Code Form is subject to the terms of the Mozilla Public
  License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -433,7 +435,7 @@ TDUContext.destroy();
 		updateDraggedTabs : function TDU_updateDraggedTabs(context)
 		{
 			context.draggedTabs.forEach(function(draggedTab, aIndex) {
-				if (aIndex > 0) {
+				if (draggedTab._dragData.canShrink && aIndex > 0) {
 					let style = draggedTab.style;
 					if (!draggedTab.__tabsDragUtils__backupStyle) {
 						let backup = {
@@ -582,8 +584,10 @@ TDUContext.destroy();
 				this.updatedTabDNDObservers = this.updatedTabDNDObservers.splice(index, 1);
 		},
 
-		startTabsDrag : function TDU_startTabsDrag(aEvent, aTabs)
+		startTabsDrag : function TDU_startTabsDrag(aEvent, aTabs, aOptions)
 		{
+			aOptions = aOptions || {};
+
 			var draggedTab = this.getTabFromEvent(aEvent);
 			var tabs = aTabs || [];
 			var index = tabs.indexOf(draggedTab);
@@ -622,15 +626,18 @@ TDUContext.destroy();
 						scrollX: isVertical ? 0 : tabbar.mTabstrip.scrollPosition ,
 						scrollY: isVertical ? tabbar.mTabstrip.scrollPosition : 0 ,
 						screenX: aEvent.screenX,
-						screenY: aEvent.screenY
+						screenY: aEvent.screenY,
+						canShrink : aOptions.shrinkOthers || false
 					};
 				}, this);
 			}
 
 			aEvent.stopPropagation();
 
+			if (aOptions.shrinkOthers) {
 			document.addEventListener('dragend', this, true);
 			document.addEventListener('drop', this, true);
+			}
 		},
 		isVertical : function TDS_isVertical(aElement)
 		{
diff --git a/defaults/preferences/treestyletab.js b/defaults/preferences/treestyletab.js
index 3932068d..27a0e3e9 100644
--- a/defaults/preferences/treestyletab.js
+++ b/defaults/preferences/treestyletab.js
@@ -671,6 +671,11 @@ pref("extensions.treestyletab.pinnedTab.faviconized", true);
 pref("extensions.treestyletab.groupTab.columnize", true);
 pref("extensions.treestyletab.groupTab.columnize.width", "20em");
 
+/**
+ * If true, other dragged tabs are shrunken while dragging.
+ */
+pref("extensions.treestyletab.shrinkOtherDraggedTabs", true);
+
 /**
  * If true, TST automatically disables Tabs in Titlebar appearance to avoid
  * broken appearance problems.
diff --git a/modules/tabbarDNDObserver.js b/modules/tabbarDNDObserver.js
index 56695ef5..7a6ab9e1 100644
--- a/modules/tabbarDNDObserver.js
+++ b/modules/tabbarDNDObserver.js
@@ -773,7 +773,9 @@ catch(e) {
 			)
 			return;
 
-		w['piro.sakura.ne.jp'].tabsDragUtils.startTabsDrag(aEvent, tabsInfo.draggedTabs);
+		w['piro.sakura.ne.jp'].tabsDragUtils.startTabsDrag(aEvent, tabsInfo.draggedTabs, {
+			shrinkOthers : utils.getTreePref('shrinkOtherDraggedTabs')
+		});
 	},
  
 	onTabbarDragStart : function TabbarDND_onTabbarDragStart(aEvent)