Refactor mouse press/release handling to support 3 buttons

Change button to be an additional parameter instead of having separate
events for left/right buttons.

Fixes #3471

doc/json_ui.asciidoc

@@ -59,11 +59,8 @@ The requests that the json ui can interpret on stdin are:
 * keys(String key1, String key2...): keystrokes
 * resize(int rows, int columns): notify ui resize
 * scroll(int amount): scroll by given line amount
-* mouse(String type, int line, int column): mouse event. line and column relate to
-  the cursor position. type can be:
-  - 'move'
-  - 'press_left'
-  - 'press_right'
-  - 'release_left'
-  - 'release_right'
+* mouse_move(int line, int column): line and column relate to the cursor position.
+* mouse_press(String button, int line, int column): line and column relate to
+  cursor position, button can be 'left', 'middle' or 'right'
+* mouse_release(String button, int line, int column): same.
 * menu_select(int index): explicit select of given menu entry

src/input_handler.cc

@@ -92,35 +92,40 @@ struct MouseHandler
         Buffer& buffer = context.buffer();
         BufferCoord cursor;
         auto& selections = context.selections();
-        constexpr auto modifiers = Key::Modifiers::Control | Key::Modifiers::Alt | Key::Modifiers::Shift;
+        constexpr auto modifiers = Key::Modifiers::Control | Key::Modifiers::Alt | Key::Modifiers::Shift | Key::Modifiers::MouseButtonMask;
         switch ((key.modifiers & ~modifiers).value)
         {
-        case Key::Modifiers::MousePressRight:
-            m_dragging = false;
-            cursor = context.window().buffer_coord(key.coord());
-            if (key.modifiers & Key::Modifiers::Control)
-                selections = {{selections.begin()->anchor(), cursor}};
-            else
-                selections.main() = {selections.main().anchor(), cursor};
-            selections.sort_and_merge_overlapping();
-            return true;
-
-        case Key::Modifiers::MousePressLeft:
-            m_dragging = true;
-            m_anchor = context.window().buffer_coord(key.coord());
-            if (not (key.modifiers & Key::Modifiers::Control))
-                context.selections_write_only() = { buffer, m_anchor};
-            else
+        case Key::Modifiers::MousePress:
+            switch (key.mouse_button())
             {
-                size_t main = selections.size();
-                selections.push_back({m_anchor});
-                selections.set_main_index(main);
+            case Key::MouseButton::Right:
+                m_dragging = false;
+                cursor = context.window().buffer_coord(key.coord());
+                if (key.modifiers & Key::Modifiers::Control)
+                    selections = {{selections.begin()->anchor(), cursor}};
+                else
+                    selections.main() = {selections.main().anchor(), cursor};
                 selections.sort_and_merge_overlapping();
-            }
-            return true;
+                return true;
 
-        case Key::Modifiers::MouseReleaseLeft:
-        case Key::Modifiers::MouseReleaseRight:
+            case Key::MouseButton::Left:
+                m_dragging = true;
+                m_anchor = context.window().buffer_coord(key.coord());
+                if (not (key.modifiers & Key::Modifiers::Control))
+                    context.selections_write_only() = { buffer, m_anchor};
+                else
+                {
+                    size_t main = selections.size();
+                    selections.push_back({m_anchor});
+                    selections.set_main_index(main);
+                    selections.sort_and_merge_overlapping();
+                }
+                return true;
+
+            default: return true;
+            }
+
+        case Key::Modifiers::MouseRelease:
             if (not m_dragging)
                 return true;
             m_dragging = false;

src/json_ui.cc

@@ -248,31 +248,30 @@ void JsonUI::eval_json(const Value& json)
                 m_on_key(key);
         }
     }
-    else if (method == "mouse")
+    else if (method == "mouse_move")
     {
-        if (params.size() != 3)
-            throw invalid_rpc_request("mouse type/coordinates not specified");
+        if (params.size() != 2)
+            throw invalid_rpc_request("mouse coordinates not specified");
 
-        if (not params[0].is_a<String>())
-            throw invalid_rpc_request("mouse type is not a string");
-        else if (not params[1].is_a<int>() or
-                 not params[2].is_a<int>())
+        if (not params[0].is_a<int>() or not params[1].is_a<int>())
             throw invalid_rpc_request("mouse coordinates are not integers");
 
-        const StringView type = params[0].as<String>();
-        const Codepoint coord = encode_coord({params[1].as<int>(), params[2].as<int>()});
-        if (type == "move")
-            m_on_key({Key::Modifiers::MousePos, coord});
-        else if (type == "press_left")
-            m_on_key({Key::Modifiers::MousePressLeft, coord});
-        else if (type == "press_right")
-            m_on_key({Key::Modifiers::MousePressRight, coord});
-        else if (type == "release_left")
-            m_on_key({Key::Modifiers::MouseReleaseLeft, coord});
-        else if (type == "release_right")
-            m_on_key({Key::Modifiers::MouseReleaseRight, coord});
-        else
-            throw invalid_rpc_request(format("invalid mouse event type: {}", type));
+        m_on_key({Key::Modifiers::MousePos, encode_coord({params[0].as<int>(), params[1].as<int>()})});
+    }
+    else if (method == "mouse_press" or method == "mouse_release")
+    {
+        if (params.size() != 3)
+            throw invalid_rpc_request("mouse button/coordinates not specified");
+
+        if (not params[0].is_a<String>())
+            throw invalid_rpc_request("mouse button is not a string");
+        if (not params[1].is_a<int>() or not params[2].is_a<int>())
+            throw invalid_rpc_request("mouse coordinates are not integers");
+
+        auto event = method == "mouse_press" ? Key::Modifiers::MousePress : Key::Modifiers::MouseRelease;
+        auto button = str_to_button(params[0].as<String>());
+
+        m_on_key({event | Key::to_modifier(button), encode_coord({params[1].as<int>(), params[2].as<int>()})});
     }
     else if (method == "scroll")
     {

src/keys.cc

@@ -157,21 +157,36 @@ KeyList parse_keys(StringView str)
     return result;
 }
 
+StringView button_to_str(Key::MouseButton button)
+{
+    switch (button)
+    {
+        case Key::MouseButton::Left: return "left";
+        case Key::MouseButton::Middle: return "middle";
+        case Key::MouseButton::Right: return "right";
+        default: kak_assert(false); throw logic_error{};
+    }
+}
+
+Key::MouseButton str_to_button(StringView str)
+{
+    if (str == "left") return Key::MouseButton::Left;
+    if (str == "middle") return Key::MouseButton::Middle;
+    if (str == "right") return Key::MouseButton::Right;
+    throw runtime_error(format("invalid mouse button name {}", str));
+}
+
 String key_to_str(Key key)
 {
     const auto coord = key.coord() + DisplayCoord{1,1};
-    switch (key.modifiers)
+    switch (Key::Modifiers(key.modifiers & ~Key::Modifiers::MouseButtonMask))
     {
         case Key::Modifiers::MousePos:
             return format("<mouse:move:{}.{}>", coord.line, coord.column);
-        case Key::Modifiers::MousePressLeft:
-            return format("<mouse:press_left:{}.{}>", coord.line, coord.column);
-        case Key::Modifiers::MousePressRight:
-            return format("<mouse:press_right:{}.{}>", coord.line, coord.column);
-        case Key::Modifiers::MouseReleaseLeft:
-            return format("<mouse:release_left:{}.{}>", coord.line, coord.column);
-        case Key::Modifiers::MouseReleaseRight:
-            return format("<mouse:release_right:{}.{}>", coord.line, coord.column);
+        case Key::Modifiers::MousePress:
+            return format("<mouse:press:{}:{}.{}>", button_to_str(key.mouse_button()), coord.line, coord.column);
+        case Key::Modifiers::MouseRelease:
+            return format("<mouse:release:{}:{}.{}>", button_to_str(key.mouse_button()), coord.line, coord.column);
         case Key::Modifiers::Scroll:
             return format("<scroll:{}>", static_cast<int>(key.key));
         case Key::Modifiers::Resize:

src/keys.hh

@@ -14,6 +14,12 @@ namespace Kakoune
 
 struct Key
 {
+    enum class MouseButton
+    {
+        Left,
+        Middle,
+        Right
+    };
     enum class Modifiers : int
     {
         None    = 0,
@@ -21,11 +27,11 @@ struct Key
         Alt     = 1 << 1,
         Shift   = 1 << 2,
 
-        MousePressLeft    = 1 << 3,
-        MousePressRight   = 1 << 4,
-        MouseReleaseLeft  = 1 << 5,
-        MouseReleaseRight = 1 << 6,
-        MousePos          = 1 << 7,
+        MousePress     = 1 << 3,
+        MouseRelease   = 1 << 4,
+        MousePos       = 1 << 5,
+        MouseButtonMask= 0b11 << 6,
+
         Scroll     = 1 << 8,
         Resize     = 1 << 9,
         MenuSelect = 1 << 10,
@@ -82,6 +88,8 @@ struct Key
     constexpr bool operator<(Key other) const { return val() < other.val(); }
 
     constexpr DisplayCoord coord() const { return {(int)((key & 0xFFFF0000) >> 16), (int)(key & 0x0000FFFF)}; }
+    constexpr MouseButton mouse_button() { return MouseButton{((int)modifiers & (int)Modifiers::MouseButtonMask) >> 6}; }
+    static Modifiers to_modifier(MouseButton button) { return Key::Modifiers{((int)button << 6) & (int)Modifiers::MouseButtonMask}; }
 
     Optional<Codepoint> codepoint() const;
 };
@@ -95,6 +103,8 @@ class StringView;
 
 KeyList parse_keys(StringView str);
 String  key_to_str(Key key);
+StringView button_to_str(Key::MouseButton button);
+Key::MouseButton str_to_button(StringView str);
 
 constexpr Key shift(Key key)
 {

src/ncurses_ui.cc

@@ -19,6 +19,7 @@
 #include <csignal>
 #include <sys/ioctl.h>
 #include <unistd.h>
+#include <strings.h>
 
 constexpr char control(char c) { return c & 037; }
 
@@ -669,19 +670,19 @@ Optional<Key> NCursesUI::get_next_key()
             return mod;
         };
 
-        auto mouse_button = [this](Key::Modifiers mod, Codepoint coord, bool left, bool release) {
-            auto mask = left ? 0x1 : 0x2;
+        auto mouse_button = [this](Key::Modifiers mod, Key::MouseButton button, Codepoint coord, bool release) {
+            auto mask = 1 << (int)button;
             if (not release)
             {
-                mod |= (m_mouse_state & mask) ? Key::Modifiers::MousePos : (left ? Key::Modifiers::MousePressLeft : Key::Modifiers::MousePressRight);
+                mod |= (m_mouse_state & mask) ? Key::Modifiers::MousePos : Key::Modifiers::MousePress;
                 m_mouse_state |= mask;
             }
             else
             {
-                mod |= left ? Key::Modifiers::MouseReleaseLeft : Key::Modifiers::MouseReleaseRight;
+                mod |= Key::Modifiers::MouseRelease;
                 m_mouse_state &= ~mask;
             }
-            return Key{mod, coord};
+            return Key{mod | Key::to_modifier(button), coord};
         };
 
         auto mouse_scroll = [this](Key::Modifiers mod, bool down) -> Key {
@@ -752,17 +753,15 @@ Optional<Key> NCursesUI::get_next_key()
             const int y = (sgr ? params[2] : next_char() - 32) - 1;
             auto coord = encode_coord({y - content_line_offset(), x});
             Key::Modifiers mod = parse_mask((b >> 2) & 0x7);
-            switch (b & 0x43)
+            switch (auto code = b & 0x43; code)
             {
-            case 0: return mouse_button(mod, coord, true, c == 'm');
-            case 2: return mouse_button(mod, coord, false, c == 'm');
+            case 0: case 1: case 2:
+                return mouse_button(mod, Key::MouseButton{code}, coord, c == 'm');
             case 3:
                 if (sgr)
                     return {};
-                if (m_mouse_state & 0x1)
-                    return mouse_button(mod, coord, true, true);
-                else if (m_mouse_state & 0x2)
-                    return mouse_button(mod, coord, false, true);
+                else if (int guess = ffs(m_mouse_state) - 1; 0 <= guess and guess < 3)
+                    return mouse_button(mod, Key::MouseButton{guess}, coord, true);
                 break;
             case 64: return mouse_scroll(mod, false);
             case 65: return mouse_scroll(mod, true);