Fix unconsistent cursor motions

- Fixes dragging one cell (alt+arrowKey)
- Cursor advances forward/backward only on insert mode (shift+enter)
- Cursor no longer advances if the operator is not successfully written
- On insert mode, erasing is performed on the former cell (not the one
under the cursor)

3 files changed, 10 insertions, 10 deletions

diff --git a/desktop/core/orca.js b/desktop/core/orca.js
index f68db17..e9b4d1e 100644
--- a/desktop/core/orca.js
+++ b/desktop/core/orca.js
@@ -39,13 +39,14 @@ function Orca (terminal, host = null) {
   }
 
   this.write = function (x, y, g) {
-    if (!g) { return }
-    if (g.length !== 1) { return }
-    if (!this.inBounds(x, y)) { return }
-    if (!this.isAllowed(g)) { return }
-    if (this.glyphAt(x, y) === g) { return }
+    if (!g) { return false }
+    if (g.length !== 1) { return false }
+    if (!this.inBounds(x, y)) { return false }
+    if (!this.isAllowed(g)) { return false }
+    if (this.glyphAt(x, y) === g) { return false }
     const index = this.indexAt(x, y)
     this.s = this.s.substr(0, index) + g + this.s.substr(index + g.length)
+    return true
   }
 
   this.clean = function (str) {
diff --git a/desktop/sources/scripts/cursor.js b/desktop/sources/scripts/cursor.js
index 889df05..961526c 100644
--- a/desktop/sources/scripts/cursor.js
+++ b/desktop/sources/scripts/cursor.js
@@ -76,15 +76,14 @@ function Cursor (terminal) {
       terminal.io.sendKey(event.key)
       return
     }
-    terminal.orca.write(this.x, this.y, g)
-    if (this.mode === 1) {
+    if (terminal.orca.write(this.x, this.y, g) && this.mode === 1) {
       this.move(1, 0)
     }
     terminal.history.record(terminal.orca.s)
   }
 
-  this.erase = function () {
-    if (this.w === 1 && this.h === 1 && terminal.orca.glyphAt(this.x, this.y) === '.') { this.move(-1, 0); return } // Backspace Effect
+  this.erase = function (bs) {
+    if (bs && this.mode === 1) { this.move(-1, 0) }
     this.eraseBlock(this.x, this.y, this.w, this.h)
     terminal.history.record(terminal.orca.s)
   }
diff --git a/desktop/sources/scripts/keyboard.js b/desktop/sources/scripts/keyboard.js
index be77ed1..e7444cc 100644
--- a/desktop/sources/scripts/keyboard.js
+++ b/desktop/sources/scripts/keyboard.js
@@ -28,7 +28,7 @@ function Keyboard (terminal) {
     if (event.metaKey) { return }
     if (event.ctrlKey) { return }
 
-    if (event.key === 'Backspace' || event.key === '.') { terminal.cursor.erase(); return }
+    if (event.key === 'Backspace' || event.key === '.') { terminal.cursor.erase(true); return }
     if (event.key === ' ' && terminal.cursor.mode === 0) { terminal.togglePlay(); event.preventDefault(); return }
     if (event.key === 'Escape') { terminal.clear(); terminal.isPaused = false; terminal.cursor.reset(); return }