widget/gtk/NativeKeyBindings.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "mozilla/ArrayUtils.h"
   7 #include "mozilla/MathAlgorithms.h"
   8 #include "mozilla/Maybe.h"
   9 #include "mozilla/NativeKeyBindingsType.h"
  10 #include "mozilla/StaticPrefs_ui.h"
  11 #include "mozilla/TextEvents.h"
  12 #include "mozilla/WritingModes.h"
  13
  14 #include "NativeKeyBindings.h"
  15 #include "nsString.h"
  16 #include "nsGtkKeyUtils.h"
  17
  18 #include <gtk/gtk.h>
  19 #include <gdk/gdkkeysyms.h>
  20 #include <gdk/gdkkeysyms-compat.h>
  21 #include <gdk/gdk.h>
  22
  23 namespace mozilla {
  24 namespace widget {
  25
  26 static nsTArray<CommandInt>* gCurrentCommands = nullptr;
  27 static bool gHandled = false;
  28
  29 inline void AddCommand(Command aCommand) {
  30   MOZ_ASSERT(gCurrentCommands);
  31   gCurrentCommands->AppendElement(static_cast<CommandInt>(aCommand));
  32 }
  33
  34 // Common GtkEntry and GtkTextView signals
  35 static void copy_clipboard_cb(GtkWidget* w, gpointer user_data) {
  36   AddCommand(Command::Copy);
  37   g_signal_stop_emission_by_name(w, "copy_clipboard");
  38   gHandled = true;
  39 }
  40
  41 static void cut_clipboard_cb(GtkWidget* w, gpointer user_data) {
  42   AddCommand(Command::Cut);
  43   g_signal_stop_emission_by_name(w, "cut_clipboard");
  44   gHandled = true;
  45 }
  46
  47 // GTK distinguishes between display lines (wrapped, as they appear on the
  48 // screen) and paragraphs, which are runs of text terminated by a newline.
  49 // We don't have this distinction, so we always use editor's notion of
  50 // lines, which are newline-terminated.
  51
  52 static const Command sDeleteCommands[][2] = {
  53     // backward, forward
  54     // CHARS
  55     {Command::DeleteCharBackward, Command::DeleteCharForward},
  56     // WORD_ENDS
  57     {Command::DeleteWordBackward, Command::DeleteWordForward},
  58     // WORDS
  59     {Command::DeleteWordBackward, Command::DeleteWordForward},
  60     // LINES
  61     {Command::DeleteToBeginningOfLine, Command::DeleteToEndOfLine},
  62     // LINE_ENDS
  63     {Command::DeleteToBeginningOfLine, Command::DeleteToEndOfLine},
  64     // PARAGRAPH_ENDS
  65     {Command::DeleteToBeginningOfLine, Command::DeleteToEndOfLine},
  66     // PARAGRAPHS
  67     {Command::DeleteToBeginningOfLine, Command::DeleteToEndOfLine},
  68     // This deletes from the end of the previous word to the beginning of the
  69     // next word, but only if the caret is not in a word.
  70     // XXX need to implement in editor
  71     {Command::DoNothing, Command::DoNothing}  // WHITESPACE
  72 };
  73
  74 static void delete_from_cursor_cb(GtkWidget* w, GtkDeleteType del_type,
  75                                   gint count, gpointer user_data) {
  76   g_signal_stop_emission_by_name(w, "delete_from_cursor");
  77   if (count == 0) {
  78     // Nothing to do.
  79     return;
  80   }
  81
  82   bool forward = count > 0;
  83
  84   // Ignore GTK's Ctrl-K keybinding introduced in GTK 3.14 and removed in
  85   // 3.18 if the user has custom bindings set. See bug 1176929.
  86   if (del_type == GTK_DELETE_PARAGRAPH_ENDS && forward && GTK_IS_ENTRY(w) &&
  87       !gtk_check_version(3, 14, 1) && gtk_check_version(3, 17, 9)) {
  88     GtkStyleContext* context = gtk_widget_get_style_context(w);
  89     GtkStateFlags flags = gtk_widget_get_state_flags(w);
  90
  91     GPtrArray* array;
  92     gtk_style_context_get(context, flags, "gtk-key-bindings", &array, nullptr);
  93     if (!array) return;
  94     g_ptr_array_unref(array);
  95   }
  96
  97   gHandled = true;
  98   if (uint32_t(del_type) >= std::size(sDeleteCommands)) {
  99     // unsupported deletion type
 100     return;
 101   }
 102
 103   if (del_type == GTK_DELETE_WORDS) {
 104     // This works like word_ends, except we first move the caret to the
 105     // beginning/end of the current word.
 106     if (forward) {
 107       AddCommand(Command::WordNext);
 108       AddCommand(Command::WordPrevious);
 109     } else {
 110       AddCommand(Command::WordPrevious);
 111       AddCommand(Command::WordNext);
 112     }
 113   } else if (del_type == GTK_DELETE_DISPLAY_LINES ||
 114              del_type == GTK_DELETE_PARAGRAPHS) {
 115     // This works like display_line_ends, except we first move the caret to the
 116     // beginning/end of the current line.
 117     if (forward) {
 118       AddCommand(Command::BeginLine);
 119     } else {
 120       AddCommand(Command::EndLine);
 121     }
 122   }
 123
 124   Command command = sDeleteCommands[del_type][forward];
 125   if (command == Command::DoNothing) {
 126     return;
 127   }
 128
 129   unsigned int absCount = Abs(count);
 130   for (unsigned int i = 0; i < absCount; ++i) {
 131     AddCommand(command);
 132   }
 133 }
 134
 135 static const Command sMoveCommands[][2][2] = {
 136     // non-extend { backward, forward }, extend { backward, forward }
 137     // GTK differentiates between logical position, which is prev/next,
 138     // and visual position, which is always left/right.
 139     // We should fix this to work the same way for RTL text input.
 140     {// LOGICAL_POSITIONS
 141      {Command::CharPrevious, Command::CharNext},
 142      {Command::SelectCharPrevious, Command::SelectCharNext}},
 143     {// VISUAL_POSITIONS
 144      {Command::CharPrevious, Command::CharNext},
 145      {Command::SelectCharPrevious, Command::SelectCharNext}},
 146     {// WORDS
 147      {Command::WordPrevious, Command::WordNext},
 148      {Command::SelectWordPrevious, Command::SelectWordNext}},
 149     {// DISPLAY_LINES
 150      {Command::LinePrevious, Command::LineNext},
 151      {Command::SelectLinePrevious, Command::SelectLineNext}},
 152     {// DISPLAY_LINE_ENDS
 153      {Command::BeginLine, Command::EndLine},
 154      {Command::SelectBeginLine, Command::SelectEndLine}},
 155     {// PARAGRAPHS
 156      {Command::LinePrevious, Command::LineNext},
 157      {Command::SelectLinePrevious, Command::SelectLineNext}},
 158     {// PARAGRAPH_ENDS
 159      {Command::BeginLine, Command::EndLine},
 160      {Command::SelectBeginLine, Command::SelectEndLine}},
 161     {// PAGES
 162      {Command::MovePageUp, Command::MovePageDown},
 163      {Command::SelectPageUp, Command::SelectPageDown}},
 164     {// BUFFER_ENDS
 165      {Command::MoveTop, Command::MoveBottom},
 166      {Command::SelectTop, Command::SelectBottom}},
 167     {// HORIZONTAL_PAGES (unsupported)
 168      {Command::DoNothing, Command::DoNothing},
 169      {Command::DoNothing, Command::DoNothing}}};
 170
 171 static void move_cursor_cb(GtkWidget* w, GtkMovementStep step, gint count,
 172                            gboolean extend_selection, gpointer user_data) {
 173   g_signal_stop_emission_by_name(w, "move_cursor");
 174   if (count == 0) {
 175     // Nothing to do.
 176     return;
 177   }
 178
 179   gHandled = true;
 180   bool forward = count > 0;
 181   if (uint32_t(step) >= std::size(sMoveCommands)) {
 182     // unsupported movement type
 183     return;
 184   }
 185
 186   Command command = sMoveCommands[step][extend_selection][forward];
 187   if (command == Command::DoNothing) {
 188     return;
 189   }
 190
 191   unsigned int absCount = Abs(count);
 192   for (unsigned int i = 0; i < absCount; ++i) {
 193     AddCommand(command);
 194   }
 195 }
 196
 197 static void paste_clipboard_cb(GtkWidget* w, gpointer user_data) {
 198   AddCommand(Command::Paste);
 199   g_signal_stop_emission_by_name(w, "paste_clipboard");
 200   gHandled = true;
 201 }
 202
 203 // GtkTextView-only signals
 204 static void select_all_cb(GtkWidget* aWidget, gboolean aSelect,
 205                           gpointer aUserData) {
 206   // We don't support "Unselect All" command.
 207   // Note that if we'd support it, `Ctrl-Shift-a` will be mapped to it and
 208   // overrides open `about:addons` shortcut.
 209   if (aSelect) {
 210     AddCommand(Command::SelectAll);
 211   }
 212   g_signal_stop_emission_by_name(aWidget, "select_all");
 213   // Although we prevent the default of `GtkTExtView` with
 214   // `g_signal_stop_emission_by_name`, but `gHandled` is used for asserting
 215   // if it does not match with the emptiness of the command array.
 216   // Therefore, we should not set it to `true` if we don't add a command.
 217   gHandled |= aSelect;
 218 }
 219
 220 NativeKeyBindings* NativeKeyBindings::sInstanceForSingleLineEditor = nullptr;
 221 NativeKeyBindings* NativeKeyBindings::sInstanceForMultiLineEditor = nullptr;
 222
 223 // static
 224 NativeKeyBindings* NativeKeyBindings::GetInstance(NativeKeyBindingsType aType) {
 225   switch (aType) {
 226     case NativeKeyBindingsType::SingleLineEditor:
 227       if (!sInstanceForSingleLineEditor) {
 228         sInstanceForSingleLineEditor = new NativeKeyBindings();
 229         sInstanceForSingleLineEditor->Init(aType);
 230       }
 231       return sInstanceForSingleLineEditor;
 232
 233     default:
 234       // fallback to multiline editor case in release build
 235       MOZ_FALLTHROUGH_ASSERT("aType is invalid or not yet implemented");
 236     case NativeKeyBindingsType::MultiLineEditor:
 237     case NativeKeyBindingsType::RichTextEditor:
 238       if (!sInstanceForMultiLineEditor) {
 239         sInstanceForMultiLineEditor = new NativeKeyBindings();
 240         sInstanceForMultiLineEditor->Init(aType);
 241       }
 242       return sInstanceForMultiLineEditor;
 243   }
 244 }
 245
 246 // static
 247 void NativeKeyBindings::Shutdown() {
 248   delete sInstanceForSingleLineEditor;
 249   sInstanceForSingleLineEditor = nullptr;
 250   delete sInstanceForMultiLineEditor;
 251   sInstanceForMultiLineEditor = nullptr;
 252 }
 253
 254 void NativeKeyBindings::Init(NativeKeyBindingsType aType) {
 255   switch (aType) {
 256     case NativeKeyBindingsType::SingleLineEditor:
 257       mNativeTarget = gtk_entry_new();
 258       break;
 259     default:
 260       mNativeTarget = gtk_text_view_new();
 261       g_signal_connect(mNativeTarget, "select_all", G_CALLBACK(select_all_cb),
 262                        this);
 263       break;
 264   }
 265
 266   g_object_ref_sink(mNativeTarget);
 267
 268   g_signal_connect(mNativeTarget, "copy_clipboard",
 269                    G_CALLBACK(copy_clipboard_cb), this);
 270   g_signal_connect(mNativeTarget, "cut_clipboard", G_CALLBACK(cut_clipboard_cb),
 271                    this);
 272   g_signal_connect(mNativeTarget, "delete_from_cursor",
 273                    G_CALLBACK(delete_from_cursor_cb), this);
 274   g_signal_connect(mNativeTarget, "move_cursor", G_CALLBACK(move_cursor_cb),
 275                    this);
 276   g_signal_connect(mNativeTarget, "paste_clipboard",
 277                    G_CALLBACK(paste_clipboard_cb), this);
 278 }
 279
 280 NativeKeyBindings::~NativeKeyBindings() {
 281   gtk_widget_destroy(mNativeTarget);
 282   g_object_unref(mNativeTarget);
 283 }
 284
 285 void NativeKeyBindings::GetEditCommands(const WidgetKeyboardEvent& aEvent,
 286                                         const Maybe<WritingMode>& aWritingMode,
 287                                         nsTArray<CommandInt>& aCommands) {
 288   MOZ_ASSERT(!aEvent.mFlags.mIsSynthesizedForTests);
 289   MOZ_ASSERT(aCommands.IsEmpty());
 290
 291   // It must be a DOM event dispached by chrome script.
 292   if (!aEvent.mNativeKeyEvent) {
 293     return;
 294   }
 295
 296   guint keyval;
 297   if (aEvent.mCharCode) {
 298     keyval = gdk_unicode_to_keyval(aEvent.mCharCode);
 299   } else if (aWritingMode.isSome() && aEvent.NeedsToRemapNavigationKey() &&
 300              aWritingMode.ref().IsVertical()) {
 301     // TODO: Use KeyNameIndex rather than legacy keyCode.
 302     uint32_t remappedGeckoKeyCode =
 303         aEvent.GetRemappedKeyCode(aWritingMode.ref());
 304     switch (remappedGeckoKeyCode) {
 305       case NS_VK_UP:
 306         keyval = GDK_Up;
 307         break;
 308       case NS_VK_DOWN:
 309         keyval = GDK_Down;
 310         break;
 311       case NS_VK_LEFT:
 312         keyval = GDK_Left;
 313         break;
 314       case NS_VK_RIGHT:
 315         keyval = GDK_Right;
 316         break;
 317       default:
 318         MOZ_ASSERT_UNREACHABLE("Add a case for the new remapped key");
 319         return;
 320     }
 321   } else {
 322     keyval = static_cast<GdkEventKey*>(aEvent.mNativeKeyEvent)->keyval;
 323   }
 324
 325   if (GetEditCommandsInternal(aEvent, aCommands, keyval)) {
 326     return;
 327   }
 328
 329   for (uint32_t i = 0; i < aEvent.mAlternativeCharCodes.Length(); ++i) {
 330     uint32_t ch = aEvent.IsShift()
 331                       ? aEvent.mAlternativeCharCodes[i].mShiftedCharCode
 332                       : aEvent.mAlternativeCharCodes[i].mUnshiftedCharCode;
 333     if (ch && ch != aEvent.mCharCode) {
 334       keyval = gdk_unicode_to_keyval(ch);
 335       if (GetEditCommandsInternal(aEvent, aCommands, keyval)) {
 336         return;
 337       }
 338     }
 339   }
 340
 341   // If the key event does not cause any commands, and we're for single line
 342   // editor, let's check whether the key combination is for "select-all" in
 343   // GtkTextView because the signal is not supported by GtkEntry.
 344   if (aCommands.IsEmpty() && this == sInstanceForSingleLineEditor &&
 345       StaticPrefs::ui_key_use_select_all_in_single_line_editor()) {
 346     if (NativeKeyBindings* bindingsForMultilineEditor =
 347             GetInstance(NativeKeyBindingsType::MultiLineEditor)) {
 348       bindingsForMultilineEditor->GetEditCommands(aEvent, aWritingMode,
 349                                                   aCommands);
 350       if (aCommands.Length() == 1u &&
 351           aCommands[0u] == static_cast<CommandInt>(Command::SelectAll)) {
 352         return;
 353       }
 354       aCommands.Clear();
 355     }
 356   }
 357
 358   /*
 359   gtk_bindings_activate_event is preferable, but it has unresolved bug:
 360   http://bugzilla.gnome.org/show_bug.cgi?id=162726
 361   The bug was already marked as FIXED.  However, somebody reports that the
 362   bug still exists.
 363   Also gtk_bindings_activate may work with some non-shortcuts operations
 364   (todo: check it). See bug 411005 and bug 406407.
 365
 366   Code, which should be used after fixing GNOME bug 162726:
 367
 368     gtk_bindings_activate_event(GTK_OBJECT(mNativeTarget),
 369       static_cast<GdkEventKey*>(aEvent.mNativeKeyEvent));
 370   */
 371 }
 372
 373 bool NativeKeyBindings::GetEditCommandsInternal(
 374     const WidgetKeyboardEvent& aEvent, nsTArray<CommandInt>& aCommands,
 375     guint aKeyval) {
 376   guint modifiers = static_cast<GdkEventKey*>(aEvent.mNativeKeyEvent)->state;
 377
 378   gCurrentCommands = &aCommands;
 379
 380   gHandled = false;
 381   gtk_bindings_activate(G_OBJECT(mNativeTarget), aKeyval,
 382                         GdkModifierType(modifiers));
 383
 384   gCurrentCommands = nullptr;
 385
 386   return gHandled;
 387 }
 388
 389 // static
 390 void NativeKeyBindings::GetEditCommandsForTests(
 391     NativeKeyBindingsType aType, const WidgetKeyboardEvent& aEvent,
 392     const Maybe<WritingMode>& aWritingMode, nsTArray<CommandInt>& aCommands) {
 393   MOZ_DIAGNOSTIC_ASSERT(aEvent.IsTrusted());
 394
 395   if (aEvent.IsAlt() || aEvent.IsMeta()) {
 396     return;
 397   }
 398
 399   static const size_t kBackward = 0;
 400   static const size_t kForward = 1;
 401   const size_t extentSelection = aEvent.IsShift() ? 1 : 0;
 402   // https://github.com/GNOME/gtk/blob/1f141c19533f4b3f397c3959ade673ce243b6138/gtk/gtktext.c#L1289
 403   // https://github.com/GNOME/gtk/blob/c5dd34344f0c660ceffffb3bf9da43c263db16e1/gtk/gtktextview.c#L1534
 404   Command command = Command::DoNothing;
 405   const KeyNameIndex remappedKeyNameIndex =
 406       aWritingMode.isSome() ? aEvent.GetRemappedKeyNameIndex(aWritingMode.ref())
 407                             : aEvent.mKeyNameIndex;
 408   switch (remappedKeyNameIndex) {
 409     case KEY_NAME_INDEX_USE_STRING:
 410       switch (aEvent.PseudoCharCode()) {
 411         case 'a':
 412         case 'A':
 413           if (aEvent.IsControl()) {
 414             command = Command::SelectAll;
 415           }
 416           break;
 417         case 'c':
 418         case 'C':
 419           if (aEvent.IsControl() && !aEvent.IsShift()) {
 420             command = Command::Copy;
 421           }
 422           break;
 423         case 'u':
 424         case 'U':
 425           if (aType == NativeKeyBindingsType::SingleLineEditor &&
 426               aEvent.IsControl() && !aEvent.IsShift()) {
 427             command = sDeleteCommands[GTK_DELETE_PARAGRAPH_ENDS][kBackward];
 428           }
 429           break;
 430         case 'v':
 431         case 'V':
 432           if (aEvent.IsControl() && !aEvent.IsShift()) {
 433             command = Command::Paste;
 434           }
 435           break;
 436         case 'x':
 437         case 'X':
 438           if (aEvent.IsControl() && !aEvent.IsShift()) {
 439             command = Command::Cut;
 440           }
 441           break;
 442         case '/':
 443           if (aEvent.IsControl() && !aEvent.IsShift()) {
 444             command = Command::SelectAll;
 445           }
 446           break;
 447         default:
 448           break;
 449       }
 450       break;
 451     case KEY_NAME_INDEX_Insert:
 452       if (aEvent.IsControl() && !aEvent.IsShift()) {
 453         command = Command::Copy;
 454       } else if (aEvent.IsShift() && !aEvent.IsControl()) {
 455         command = Command::Paste;
 456       }
 457       break;
 458     case KEY_NAME_INDEX_Delete:
 459       if (aEvent.IsShift()) {
 460         command = Command::Cut;
 461         break;
 462       }
 463       [[fallthrough]];
 464     case KEY_NAME_INDEX_Backspace: {
 465       const size_t direction =
 466           remappedKeyNameIndex == KEY_NAME_INDEX_Delete ? kForward : kBackward;
 467       const GtkDeleteType amount =
 468           aEvent.IsControl() && aEvent.IsShift()
 469               ? GTK_DELETE_PARAGRAPH_ENDS
 470               // FYI: Shift key for Backspace is ignored to help mis-typing.
 471               : (aEvent.IsControl() ? GTK_DELETE_WORD_ENDS : GTK_DELETE_CHARS);
 472       command = sDeleteCommands[amount][direction];
 473       break;
 474     }
 475     case KEY_NAME_INDEX_ArrowLeft:
 476     case KEY_NAME_INDEX_ArrowRight: {
 477       const size_t direction = remappedKeyNameIndex == KEY_NAME_INDEX_ArrowRight
 478                                    ? kForward
 479                                    : kBackward;
 480       const GtkMovementStep amount = aEvent.IsControl()
 481                                          ? GTK_MOVEMENT_WORDS
 482                                          : GTK_MOVEMENT_VISUAL_POSITIONS;
 483       command = sMoveCommands[amount][extentSelection][direction];
 484       break;
 485     }
 486     case KEY_NAME_INDEX_ArrowUp:
 487     case KEY_NAME_INDEX_ArrowDown: {
 488       const size_t direction = remappedKeyNameIndex == KEY_NAME_INDEX_ArrowDown
 489                                    ? kForward
 490                                    : kBackward;
 491       const GtkMovementStep amount = aEvent.IsControl()
 492                                          ? GTK_MOVEMENT_PARAGRAPHS
 493                                          : GTK_MOVEMENT_DISPLAY_LINES;
 494       command = sMoveCommands[amount][extentSelection][direction];
 495       break;
 496     }
 497     case KEY_NAME_INDEX_Home:
 498     case KEY_NAME_INDEX_End: {
 499       const size_t direction =
 500           remappedKeyNameIndex == KEY_NAME_INDEX_End ? kForward : kBackward;
 501       const GtkMovementStep amount = aEvent.IsControl()
 502                                          ? GTK_MOVEMENT_BUFFER_ENDS
 503                                          : GTK_MOVEMENT_DISPLAY_LINE_ENDS;
 504       command = sMoveCommands[amount][extentSelection][direction];
 505       break;
 506     }
 507     case KEY_NAME_INDEX_PageUp:
 508     case KEY_NAME_INDEX_PageDown: {
 509       const size_t direction = remappedKeyNameIndex == KEY_NAME_INDEX_PageDown
 510                                    ? kForward
 511                                    : kBackward;
 512       const GtkMovementStep amount = aEvent.IsControl()
 513                                          ? GTK_MOVEMENT_HORIZONTAL_PAGES
 514                                          : GTK_MOVEMENT_PAGES;
 515       command = sMoveCommands[amount][extentSelection][direction];
 516       break;
 517     }
 518     default:
 519       break;
 520   }
 521   if (command != Command::DoNothing) {
 522     aCommands.AppendElement(static_cast<CommandInt>(command));
 523   }
 524 }
 525
 526 }  // namespace widget
 527 }  // namespace mozilla