Ctrl-L (Clear) blanks the current window.

Problems:
* Bug#709811	https://bugzilla.gnome.org/show_bug.cgi?id=709811
* Bug#550885	https://bugzilla.gnome.org/show_bug.cgi?id=550885

Will Thompson (last bug report) has proposed to design the clearance of the
chat window like in a linux terminal. I think, thats a good idea and it
solves also the upper problem (that some parts of the history are deleted
and older ones, which were not displayed before the clearance command, show
up by scrolling up)

I changed empathy_theme_adium_clear() so that the Javascript function
'clearPage()' is exectued instead of re-loading the template. The
Javascipt function is implemented in the data/Template html file.

2 files changed, 57 insertions, 1 deletions

diff --git a/data/Template.html b/data/Template.html
index 295ba8b84..2b1ec215b 100644
--- a/data/Template.html
+++ b/data/Template.html
@@ -26,6 +26,7 @@
 			this.isCoalescing = false;
 			this.isConsecutive = undefined;
 			this.shouldScroll = undefined;
+			this.interdiv = undefined;
 			
 			var appendElement = function (elem) {
 				document.getElementById("Chat").appendChild(elem);
@@ -101,6 +102,22 @@
 				}
 			}
 			
+			// This method is called, if the size of the chat window
+			// changes or after new messages have been appended.
+			// Adjusts the size of the interleaving page (if existing)
+			this.onchange = function() {
+				if (self.interdiv !== undefined){
+					var old_padding = parseInt(self.interdiv.style.paddingTop, 10);
+					var diff = document.height -
+						   (self.interdiv.offsetTop + old_padding);
+					new_padding = window.innerHeight - diff;
+
+					if (new_padding <= 0)
+						removePage();
+					else
+						self.interdiv.style.paddingTop = new_padding + "px";
+				}
+			}
 			
 			// coalased analogs to the global functions
 			
@@ -118,6 +135,7 @@
 				node = null;
 
 				setShouldScroll(shouldScroll);
+				self.onchange();
 				self.coalesce();
 			}
 			
@@ -133,6 +151,7 @@
 				}
 				node = null;
 				setShouldScroll(shouldScroll);
+				self.onchange();
 				self.coalesce();
 			}
 			
@@ -305,6 +324,7 @@
 
 		window.onresize = function windowDidResize(){
 			alignChat(true/*nearBottom()*/); //nearBottom buggy with inactive tabs
+			window.onresize = coalescedHTML.onchange;
 		}
 		
 		function initStyle() {
@@ -312,6 +332,41 @@
 			if(!coalescedHTML)
 				coalescedHTML = new CoalescedHTML();
 		}
+
+		/* Implementation of the CTRL-L command to clear the chat
+                 * window. (Similar to a linux terminal)
+                 */
+		function clearPage(){
+			removePage();
+			if (checkForAndRemoveInsertNodes()){
+				var interdiv = document.createElement('div');
+				interdiv.id = 'interleaving_page';
+				interdiv.style.paddingTop = window.innerHeight + 'px';
+				chat.appendChild(interdiv);
+				coalescedHTML.interdiv = interdiv;
+			}
+		}
+
+		function checkForAndRemoveInsertNodes() {
+			var inserts = chat.querySelectorAll("#insert");
+			if (inserts.length <= 0){
+				return false;
+			}
+			for (var n = 0; n < inserts.length-1; n++) {
+				var rm = inserts[n];
+				rm.parentNode.removeChild(rm);
+			}
+			return true;
+		}
+
+		function removePage(){
+			var interdivs = chat.querySelectorAll("#interleaving_page");
+			if (interdivs.length > 0){
+				var rm = interdivs[0];
+				rm.parentNode.removeChild(rm);
+			}
+			coalescedHTML.interdiv = undefined;
+		}
 	</script>
 
 	<style type="text/css">
diff --git a/libempathy-gtk/empathy-theme-adium.c b/libempathy-gtk/empathy-theme-adium.c
index 79cbabb9e..5c5b7a7ea 100644
--- a/libempathy-gtk/empathy-theme-adium.c
+++ b/libempathy-gtk/empathy-theme-adium.c
@@ -1288,7 +1288,8 @@ empathy_theme_adium_get_has_selection (EmpathyThemeAdium *self)
 void
 empathy_theme_adium_clear (EmpathyThemeAdium *self)
 {
-  theme_adium_load_template (self);
+  webkit_web_view_execute_script (WEBKIT_WEB_VIEW (self), "clearPage()");
+  empathy_theme_adium_scroll_down (self);
 
   /* Clear last contact to avoid trying to add a 'joined'
    * message when we don't have an insertion point. */