keys: Update key layout for easier matrix/vector entry

Map shift-9 to enter matrices and vector, and delegate `MatrixMenu` to
secondary shift. The `MatrixMenu` is easy to access through the
`ToolMenu` anyway as soon as a matrix is on the stack, so having a
single-shifted menu is not that important.

Fixes: #198

Signed-off-by: Christophe de Dinechin <christophe@dinechin.org>

src/tests.cc

@@ -2443,8 +2443,8 @@ tests &tests::itest(cstring txt)
         case '^': k = INV;          alpha = true;  shift = true;  break;
         case '(': k = XEQ;          alpha = true;  shift = true;  del = true; break;
         case ')': k = XEQ;          alpha = true;  shift = true;  bsp = true; break;
-        case '[': k = KEY9;         alpha = true; xshift = true;  del = true; break;
-        case ']': k = KEY9;         alpha = true; xshift = true;  bsp = true; break;
+        case '[': k = KEY9;         alpha = false; shift = true;  del = true; break;
+        case ']': k = KEY9;         alpha = false; shift = true;  bsp = true; break;
         case '{': k = RUNSTOP;      alpha = true; xshift = true;  del = true; break;
         case '}': k = RUNSTOP;      alpha = true; xshift = true;  bsp = true; break;
         case '"': k = ENTER;        alpha = true; xshift = true;  bsp = true; break;

src/user_interface.cc

@@ -2561,6 +2561,16 @@ bool user_interface::handle_editing(int key)
                 return true;
             }
             break;
+
+        case KEY_9:
+            if (shift)
+            {
+                // Shift-9 enters a matrix
+                edit('[', MATRIX);
+                last = 0;
+                return true;
+            }
+            break;
         }
     }
 
@@ -3035,7 +3045,7 @@ static const byte defaultShiftedCommand[2*user_interface::NUM_KEYS] =
     OP2BYTES(KEY_UP,    0),
     OP2BYTES(KEY_7,     menu::ID_SolverMenu),
     OP2BYTES(KEY_8,     menu::ID_SymbolicMenu),
-    OP2BYTES(KEY_9,     menu::ID_MatrixMenu),
+    OP2BYTES(KEY_9,     0),     // Insert []
     OP2BYTES(KEY_DIV,   menu::ID_StatisticsMenu),
     OP2BYTES(KEY_DOWN,  0),
     OP2BYTES(KEY_4,     menu::ID_BasesMenu),
@@ -3092,7 +3102,7 @@ static const byte defaultSecondShiftedCommand[2*user_interface::NUM_KEYS] =
     OP2BYTES(KEY_UP,    0),
     OP2BYTES(KEY_7,     0),
     OP2BYTES(KEY_8,     0),
-    OP2BYTES(KEY_9,     0),
+    OP2BYTES(KEY_9,     menu::ID_MatrixMenu),
     OP2BYTES(KEY_DIV,   0),
     OP2BYTES(KEY_DOWN,  0),
     OP2BYTES(KEY_4,     0),