From cdd4ae34eb2c8f8c26f8f2b9002a00bbdc7b092b Mon Sep 17 00:00:00 2001
From: zodiac <zodiac@0da03de8-d603-11dd-86c2-0f8696b7b6f9>
Date: Thu, 19 Mar 2009 22:10:48 +0000
Subject: [PATCH] Tweaked cursor positioning code, and added explicit no-cache
 headers to our responses. This might help with reported IE6 problems.

git-svn-id: https://shellinabox.googlecode.com/svn/trunk@81 0da03de8-d603-11dd-86c2-0f8696b7b6f9
---
 ChangeLog                  |  8 +++++++
 config.h                   |  2 +-
 shellinabox/shellinaboxd.c |  1 +
 shellinabox/styles.css     |  7 +++++-
 shellinabox/vt100.js       | 48 +++++++++++++++++++++++++++++---------
 5 files changed, 53 insertions(+), 13 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 32c14af..6dfb598 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2009-03-19  Markus Gutschke  <markus@shellinabox.com>
+
+	* Fixed cursor positioning. Hopefully, more browsers will be happy
+	with this, now.
+
+	* Explicitly added no-cache headers to our responses. This might help
+	with the IE6 problems.
+
 2009-03-17  Markus Gutschke  <markus@shellinabox.com>
 
 	* Allow root to bind to privileged port.
diff --git a/config.h b/config.h
index a386fe4..166e566 100644
--- a/config.h
+++ b/config.h
@@ -95,7 +95,7 @@
 #define STDC_HEADERS 1
 
 /* Most recent revision number in the version control system */
-#define VCS_REVISION "80"
+#define VCS_REVISION "81"
 
 /* Version number of package */
 #define VERSION "2.4"
diff --git a/shellinabox/shellinaboxd.c b/shellinabox/shellinaboxd.c
index f35234f..c51a697 100644
--- a/shellinabox/shellinaboxd.c
+++ b/shellinabox/shellinaboxd.c
@@ -225,6 +225,7 @@ static int completePendingRequest(struct Session *session,
                                              "Content-Type: application/json; "
                                              "charset=utf-8\r\n"
                                              "Content-Length: %ld\r\n"
+                                             "Cache-Control: no-cache\r\n"
                                              "\r\n"
                                              "%s",
                                              (long)strlen(json),
diff --git a/shellinabox/styles.css b/shellinabox/styles.css
index 31ae4cf..0833fb2 100644
--- a/shellinabox/styles.css
+++ b/shellinabox/styles.css
@@ -20,10 +20,15 @@
   padding:          1px;
 }
 
-#vt100 #console, #vt100 #alt_console, #vt100 #cursor { 
+#vt100 #console, #vt100 #alt_console, #vt100 #cursor, #vt100 #lineheight { 
   font-family:      "DejaVu Sans Mono", "Everson Mono", FreeMono, "Andale Mono", "Lucida Console", monospace;
 }
 
+#vt100 #lineheight { 
+  position:         absolute;
+  visibility:       hidden;
+}
+
 #vt100 #cursor {
   position:         absolute;
   left:             0px;
diff --git a/shellinabox/vt100.js b/shellinabox/vt100.js
index 7e7c50d..39f63a4 100644
--- a/shellinabox/vt100.js
+++ b/shellinabox/vt100.js
@@ -234,11 +234,11 @@ VT100.prototype.initializeElements = function(container) {
                        '</div>' +
                        '<div id="menu"></div>' +
                        '<div id="scrollable">' +
+                         '<pre id="lineheight">&nbsp;</pre>' +
                          '<pre id="console"></pre>' +
                          '<pre id="alt_console" style="display: none"></pre>' +
                          '<div id="padding"></div>' +
-                         '<pre id="cursor">&nbsp;</pre>' +
-                         '<pre id="lineheight">&nbsp;</pre>' +
+                         '<pre id="cursor">X</pre>' +
                        '</div>' +
                        '<div class="hidden">' +
                          '<input type="textfield" id="input" />' +
@@ -982,28 +982,54 @@ VT100.prototype.putString = function(x, y, text, style) {
       this.cursorX                  = 0;
     }
   }
+  var pixelX                        = -1;
+  var pixelY                        = -1;
   if (!this.cursor.style.visibility) {
     var idx                         = this.cursorX - xPos;
     if (span) {
-      var nxtIdx                    = idx - this.getTextContent(span).length;
+      // If we are in a non-empty line, take the cursor Y position from the
+      // other elements in this line. If dealing with broken, non-proportional
+      // fonts, this is likely to yield better results.
+      pixelY                        = span.offsetTop;
+
+      s                             = this.getTextContent(span);
+      var nxtIdx                    = idx - s.length;
       if (nxtIdx < 0) {
-        this.setTextContent(this.cursor,
-                            this.getTextContent(span).charAt(idx));
-      } else if (span.nextSibling) {
-        this.setTextContent(this.cursor,
-                         this.getTextContent(span.nextSibling).charAt(nxtIdx));
+        this.setTextContent(this.cursor, s.charAt(idx));
+        pixelX                      = span.offsetLeft +
+                                      idx*span.offsetWidth / s.length;
       } else {
-        this.setTextContent(this.cursor, ' ');
+        if (nxtIdx == 0) {
+          pixelX                    = span.offsetLeft + span.offsetWidth;
+        }
+        if (span.nextSibling) {
+          s                         = this.getTextContent(span.nextSibling);
+          this.setTextContent(this.cursor, s.charAt(nxtIdx));
+          if (pixelX < 0) {
+            pixelX                  = span.nextSibling.offsetLeft +
+                                      nxtIdx*span.offsetWidth / s.length;
+          }
+        } else {
+          this.setTextContent(this.cursor, ' ');
+        }
       }
     } else {
       this.setTextContent(this.cursor, ' ');
     }
   }
-  this.cursor.style.left            = this.cursorX*this.cursorWidth +
+  if (pixelX >= 0) {
+    this.cursor.style.left          = pixelX + 'px';
+  } else {
+    this.cursor.style.left          = this.cursorX*this.cursorWidth +
                                       console.offsetLeft + 'px';
+  }
   this.cursorY                      = yIdx - this.numScrollbackLines;
-  this.cursor.style.top             = yIdx*this.cursorHeight +
+  if (pixelY >= 0) {
+    this.cursor.style.top           = pixelY + 'px';
+  } else {
+    this.cursor.style.top           = yIdx*this.cursorHeight +
                                       console.offsetTop + 'px';
+  }
 
   if (text.length) {
     // Merge <span> with previous sibling, if styles are identical