Bug 1027670 - Improve jump when press enter

apps/keyboard/js/imes/latex/latex.js

@@ -103,6 +103,43 @@
     }
   }
 
+  function computeJumpLegth(textAfterCursor) {
+    var LaTeXJumpRegex =
+      /(\\r(ight(\)|\]|\\\})|angle|ang|ceil|floor)|\\end\{\w+\}|\]|\\?\}|\\?\||\$)/;
+
+    var LaTeXJumpMatch = textAfterCursor.match(LaTeXJumpRegex);
+    if (LaTeXJumpMatch) {
+      if (LaTeXJumpMatch[0].startsWith('\\r') ||
+          LaTeXJumpMatch[0].startsWith('\\end')) {
+        // If match one delimiter, jump to the end of it.
+        return LaTeXJumpMatch.index + LaTeXJumpMatch[0].length;
+      } else {
+        // If LaTeXJumpMatch start at the begin of textAfterCursor we need
+        // to do something otherwise the cursor will not move.
+        if (LaTeXJumpMatch.index === 0) {
+          if (textAfterCursor.length === LaTeXJumpMatch[0].length) {
+            // If the match is the text after cursor we move to the end of it.
+            return LaTeXJumpMatch[0].length;
+          } else if (textAfterCursor[LaTeXJumpMatch[0].length] === '\\') {
+            // If the next char after the match is '\' we move before it.
+            return LaTeXJumpMatch[0].length;
+          } else if (textAfterCursor[LaTeXJumpMatch[0].length] === ' ') {
+            // If the next char after the match is ' ' we move after it.
+            return LaTeXJumpMatch[0].length + 1;
+          } else {
+            // Otherwise we need to search for another match.
+            return LaTeXJumpMatch[0].length +
+              computeJumpLegth(textAfterCursor.slice(LaTeXJumpMatch[0].length));
+          }
+        } else {
+          return LaTeXJumpMatch.index;
+        }
+      }
+    } else {
+      return 0;
+    }
+  }
+
   /*
    * Return key is used to jump inside and outside LaTeX commands and
    * environment. Jump inside is need because of \underset{}{\overset{}{}}.
@@ -111,36 +148,18 @@
    *
    */
   function handleReturn() {
-    var LaTeXCommandEndRegex = /[}\]\|\$]/;
     // Use 72 for the threshold because it was the suggested value for long text
     // at PEP8 line size.
     var jumpThreshold = 72;
-
-    var jumpLength, jumpLengthAfterMatch;
     var textAfterCursor = keyboard.app.inputContext.textAfterCursor;
     // Avoid jump to next paragraph
     textAfterCursor = textAfterCursor.split('\n')[0];
     // Allow only small jumps
     textAfterCursor = textAfterCursor.slice(0, jumpThreshold);
-    var matchLaTeXCommandEnd = textAfterCursor.match(LaTeXCommandEndRegex);
-    if (matchLaTeXCommandEnd) {
-      // If matchLaTeXCommandEnd start at the begin of textAfterCursor we need
-      // to do something otherwise the cursor will not move.
-      if (matchLaTeXCommandEnd.index === 0) {
-        // If the is only one char after the cursor we move after it. Otherwise
-        // we move to the next match.
-        if (textAfterCursor.length === 1) {
-          jumpLengthAfterMatch = 1;
-        } else {
-          textAfterCursor = textAfterCursor.slice(1);
-          matchLaTeXCommandEnd = textAfterCursor.match(LaTeXCommandEndRegex);
-          jumpLengthAfterMatch = 1 + matchLaTeXCommandEnd.index;
-        }
-      } else {
-        jumpLengthAfterMatch = matchLaTeXCommandEnd.index;
-      }
-      jumpLength = keyboard.app.inputContext.selectionStart +
-          jumpLengthAfterMatch;
+
+    var jumpLength = computeJumpLegth(textAfterCursor);
+    if (jumpLength > 0) {
+      jumpLength += keyboard.app.inputContext.selectionStart;
       keyboard.app.inputContext.setSelectionRange(jumpLength, 0);
     } else {
       keyboard.sendKey(RETURN);
@@ -153,13 +172,13 @@
    *
    */
   function handleBackspace() {
-    var lastWordRegex = /\\(\w+|\|)$/;
+    var lastWordRegex = /\\(\w+|\||\{)$/;
     var numberOfBackspacesToEmit = 1;
     var wordsBeforeCursor = keyboard.app.inputContext.textBeforeCursor;
 
     var lastWordMatch = wordsBeforeCursor.match(lastWordRegex);
     if (lastWordMatch) {
-      numberOfBackspacesToEmit = lastWordMatch[lastWordMatch.length - 1].length;
+      numberOfBackspacesToEmit = lastWordMatch[0].length;
     }
 
     for (var i = 0; i < numberOfBackspacesToEmit; i++) {