InlineEdit: Make cursor blink rate customizable

Codemirror supports out of the box customizability of cursor blink
rate. Half-period in milliseconds is used for cursor blinking. The
default blink rate in Codemirror is 530ms. Default in inline editor
is 0: blinking is disabled.

Change-Id: Ie54063f3ba11e98dcebaf727e29b50093258c028

gerrit-gwtui/src/main/java/com/google/gerrit/client/editor/EditPreferencesBox.java

@@ -56,6 +56,7 @@ class EditPreferencesBox extends Composite {
   @UiField Anchor close;
   @UiField NpIntTextBox tabWidth;
   @UiField NpIntTextBox lineLength;
+  @UiField NpIntTextBox cursorBlinkRate;
   @UiField ToggleButton topMenu;
   @UiField ToggleButton syntaxHighlighting;
   @UiField ToggleButton showTabs;
@@ -78,6 +79,7 @@ class EditPreferencesBox extends Composite {
 
     tabWidth.setIntValue(prefs.tabSize());
     lineLength.setIntValue(prefs.lineLength());
+    cursorBlinkRate.setIntValue(prefs.cursorBlinkRate());
     topMenu.setValue(!prefs.hideTopMenu());
     syntaxHighlighting.setValue(prefs.syntaxHighlighting());
     showTabs.setValue(prefs.showTabs());
@@ -105,6 +107,17 @@ class EditPreferencesBox extends Composite {
     }
   }
 
+  @UiHandler("cursorBlinkRate")
+  void onCursoBlinkRate(ValueChangeEvent<String> e) {
+    String v = e.getValue();
+    if (v != null && v.length() > 0) {
+      // A negative value hides the cursor entirely:
+      // don't let user shoot himself in the foot.
+      prefs.cursorBlinkRate(Math.max(0, Integer.parseInt(v)));
+      view.getEditor().setOption("cursorBlinkRate", prefs.cursorBlinkRate());
+    }
+  }
+
   @UiHandler("topMenu")
   void onTopMenu(ValueChangeEvent<Boolean> e) {
     prefs.hideTopMenu(!e.getValue());

gerrit-gwtui/src/main/java/com/google/gerrit/client/editor/EditPreferencesBox.ui.xml

@@ -181,6 +181,12 @@ limitations under the License.
             visibleLength='4'
             alignment='RIGHT'/></td>
       </tr>
+      <tr>
+        <th><ui:msg>Cursor Blink Rate</ui:msg></th>
+        <td><x:NpIntTextBox ui:field='cursorBlinkRate'
+            visibleLength='4'
+            alignment='RIGHT'/></td>
+      </tr>
       <tr>
         <th><ui:msg>Top Menu</ui:msg></th>
         <td><g:ToggleButton ui:field='topMenu'>

gerrit-gwtui/src/main/java/com/google/gerrit/client/editor/EditScreen.java

@@ -441,7 +441,7 @@ public class EditScreen extends Screen {
     cm = CodeMirror.create(editor, Configuration.create()
         .set("value", content)
         .set("readOnly", false)
-        .set("cursorBlinkRate", 0)
+        .set("cursorBlinkRate", prefs.cursorBlinkRate())
         .set("cursorHeight", 0.85)
         .set("lineNumbers", prefs.hideLineNumbers())
         .set("tabSize", prefs.tabSize())