Auto merge of #11950 - jdm:keylayout2, r=emilio

Support non-QWERTY keyboards

Using the ReceivedCharacter event from glutin, we can obtain the actual key characters that the user is pressing and releasing. This gets passed to the script thread along with the physical key data, since KeyboardEvent needs both pieces of information, where they get merged into a single logical key that gets processed by clients like TextInput without any special changes.

Tested by switching my macbook keyboard to dvorak and looking at the output of keypress/keyup/keydown event listeners, as well as playing with tests/html/textarea.html. Non-content keybindings like reload work as expected, too - the remapped keybinding triggers the reload action.

---
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #4144
- [X] These changes do not require tests because I can't think of a way to test remapped keyboard input

Fixes  #11991.

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="35" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/11950)
<!-- Reviewable:end -->

1 files changed, 25 insertions, 43 deletions

diff --git a/components/script/textinput.rs b/components/script/textinput.rs
index a56bd983f34..871af9637c0 100644
--- a/components/script/textinput.rs
+++ b/components/script/textinput.rs
@@ -6,7 +6,7 @@
 
 use clipboard_provider::ClipboardProvider;
 use dom::bindings::str::DOMString;
-use dom::keyboardevent::{KeyboardEvent, key_value};
+use dom::keyboardevent::KeyboardEvent;
 use msg::constellation_msg::{ALT, CONTROL, SHIFT, SUPER};
 use msg::constellation_msg::{Key, KeyModifiers};
 use std::borrow::ToOwned;
@@ -120,24 +120,6 @@ fn is_control_key(mods: KeyModifiers) -> bool {
     mods.contains(CONTROL) && !mods.contains(SUPER | ALT)
 }
 
-fn is_printable_key(key: Key) -> bool {
-    match key {
-        Key::Space | Key::Apostrophe | Key::Comma | Key::Minus |
-        Key::Period | Key::Slash | Key::GraveAccent | Key::Num0 |
-        Key::Num1 | Key::Num2 | Key::Num3 | Key::Num4 | Key::Num5 |
-        Key::Num6 | Key::Num7 | Key::Num8 | Key::Num9 | Key::Semicolon |
-        Key::Equal | Key::A | Key::B | Key::C | Key::D | Key::E | Key::F |
-        Key::G | Key::H | Key::I | Key::J | Key::K | Key::L | Key::M | Key::N |
-        Key::O | Key::P | Key::Q | Key::R | Key::S | Key::T | Key::U | Key::V |
-        Key::W | Key::X | Key::Y | Key::Z | Key::LeftBracket | Key::Backslash |
-        Key::RightBracket | Key::Kp0 | Key::Kp1 | Key::Kp2 | Key::Kp3 |
-        Key::Kp4 | Key::Kp5 | Key::Kp6 | Key::Kp7 | Key::Kp8 | Key::Kp9 |
-        Key::KpDecimal | Key::KpDivide | Key::KpMultiply | Key::KpSubtract |
-        Key::KpAdd | Key::KpEqual => true,
-        _ => false,
-    }
-}
-
 /// The length in bytes of the first n characters in a UTF-8 string.
 ///
 /// If the string has fewer than n characters, returns the length of the whole string.
@@ -486,80 +468,80 @@ impl<T: ClipboardProvider> TextInput<T> {
     /// Process a given `KeyboardEvent` and return an action for the caller to execute.
     pub fn handle_keydown(&mut self, event: &KeyboardEvent) -> KeyReaction {
         if let Some(key) = event.get_key() {
-            self.handle_keydown_aux(key, event.get_key_modifiers())
+            self.handle_keydown_aux(event.printable(), key, event.get_key_modifiers())
         } else {
             KeyReaction::Nothing
         }
     }
-    pub fn handle_keydown_aux(&mut self, key: Key, mods: KeyModifiers) -> KeyReaction {
+
+    pub fn handle_keydown_aux(&mut self,
+                              printable: Option<char>,
+                              key: Key,
+                              mods: KeyModifiers) -> KeyReaction {
         let maybe_select = if mods.contains(SHIFT) { Selection::Selected } else { Selection::NotSelected };
-        match key {
-            Key::A if is_control_key(mods) => {
+        match (printable, key) {
+            (Some('a'), _) if is_control_key(mods) => {
                 self.select_all();
                 KeyReaction::RedrawSelection
             },
-            Key::C if is_control_key(mods) => {
+            (Some('c'), _) if is_control_key(mods) => {
                 if let Some(text) = self.get_selection_text() {
                     self.clipboard_provider.set_clipboard_contents(text);
                 }
                 KeyReaction::DispatchInput
             },
-            Key::V if is_control_key(mods) => {
+            (Some('v'), _) if is_control_key(mods) => {
                 let contents = self.clipboard_provider.clipboard_contents();
                 self.insert_string(contents);
                 KeyReaction::DispatchInput
             },
-            _ if is_printable_key(key) => {
-                self.insert_string(key_value(key, mods));
-                KeyReaction::DispatchInput
-            }
-            Key::Space => {
-                self.insert_char(' ');
+            (Some(c), _) => {
+                self.insert_char(c);
                 KeyReaction::DispatchInput
             }
-            Key::Delete => {
+            (None, Key::Delete) => {
                 self.delete_char(Direction::Forward);
                 KeyReaction::DispatchInput
             }
-            Key::Backspace => {
+            (None, Key::Backspace) => {
                 self.delete_char(Direction::Backward);
                 KeyReaction::DispatchInput
             }
-            Key::Left => {
+            (None, Key::Left) => {
                 self.adjust_horizontal_by_one(Direction::Backward, maybe_select);
                 KeyReaction::RedrawSelection
             }
-            Key::Right => {
+            (None, Key::Right) => {
                 self.adjust_horizontal_by_one(Direction::Forward, maybe_select);
                 KeyReaction::RedrawSelection
             }
-            Key::Up => {
+            (None, Key::Up) => {
                 self.adjust_vertical(-1, maybe_select);
                 KeyReaction::RedrawSelection
             }
-            Key::Down => {
+            (None, Key::Down) => {
                 self.adjust_vertical(1, maybe_select);
                 KeyReaction::RedrawSelection
             }
-            Key::Enter | Key::KpEnter => self.handle_return(),
-            Key::Home => {
+            (None, Key::Enter) | (None, Key::KpEnter) => self.handle_return(),
+            (None, Key::Home) => {
                 self.edit_point.index = 0;
                 KeyReaction::RedrawSelection
             }
-            Key::End => {
+            (None, Key::End) => {
                 self.edit_point.index = self.current_line_length();
                 self.assert_ok_selection();
                 KeyReaction::RedrawSelection
             }
-            Key::PageUp => {
+            (None, Key::PageUp) => {
                 self.adjust_vertical(-28, maybe_select);
                 KeyReaction::RedrawSelection
             }
-            Key::PageDown => {
+            (None, Key::PageDown) => {
                 self.adjust_vertical(28, maybe_select);
                 KeyReaction::RedrawSelection
             }
-            Key::Tab => KeyReaction::TriggerDefaultAction,
+            (None, Key::Tab) => KeyReaction::TriggerDefaultAction,
             _ => KeyReaction::Nothing,
         }
     }