From e043fef25744605d3987c8f6d8ece6e6d68ae565 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Tue, 7 Mar 2023 07:57:14 +0530
Subject: [PATCH] Synthesize click events in the loop

---
 tools/tui/loop/api.go   |  2 ++
 tools/tui/loop/mouse.go | 11 ++++++-----
 tools/tui/loop/run.go   | 33 ++++++++++++++++++++++++++++++++-
 3 files changed, 40 insertions(+), 6 deletions(-)

diff --git a/tools/tui/loop/api.go b/tools/tui/loop/api.go
index f80a53d7e..7f66cb7f7 100644
--- a/tools/tui/loop/api.go
+++ b/tools/tui/loop/api.go
@@ -6,6 +6,7 @@ import (
 	"encoding/base64"
 	"fmt"
 	"kitty/tools/tty"
+	"kitty/tools/utils"
 	"strings"
 	"time"
 
@@ -56,6 +57,7 @@ type Loop struct {
 	timer_id_counter, write_msg_id_counter IdType
 	wakeup_channel                         chan byte
 	pending_writes                         []*write_msg
+	pending_mouse_events                   *utils.RingBuffer[MouseEvent]
 	on_SIGTSTP                             func() error
 
 	// Suspend the loop restoring terminal state. Call the return resume function to restore the loop
diff --git a/tools/tui/loop/mouse.go b/tools/tui/loop/mouse.go
index b927cb3d3..1a1830ed9 100644
--- a/tools/tui/loop/mouse.go
+++ b/tools/tui/loop/mouse.go
@@ -19,6 +19,7 @@ const (
 	MOUSE_PRESS MouseEventType = iota
 	MOUSE_RELEASE
 	MOUSE_MOVE
+	MOUSE_CLICK
 )
 const (
 	SHIFT_INDICATOR  int = 1 << 2
@@ -38,7 +39,7 @@ type MouseEvent struct {
 	Event_type  MouseEventType
 	Buttons     MouseButtonFlag
 	Mods        KeyModifiers
-	Cell, Pixel struct{ x, y int }
+	Cell, Pixel struct{ X, Y int }
 }
 
 func pixel_to_cell(px, length, cell_length int) int {
@@ -56,14 +57,14 @@ func decode_sgr_mouse(text string, screen_size ScreenSize) *MouseEvent {
 		return nil
 	}
 	ans := MouseEvent{}
-	ans.Pixel.x, err = strconv.Atoi(parts[1])
+	ans.Pixel.X, err = strconv.Atoi(parts[1])
 	if err != nil {
 		return nil
 	}
 	if len(parts[2]) < 1 {
 		return nil
 	}
-	ans.Pixel.y, err = strconv.Atoi(parts[2][:len(parts[2])-1])
+	ans.Pixel.Y, err = strconv.Atoi(parts[2][:len(parts[2])-1])
 	m := parts[2][len(parts[2])-1]
 	if m == 'm' {
 		ans.Event_type = MOUSE_RELEASE
@@ -87,8 +88,8 @@ func decode_sgr_mouse(text string, screen_size ScreenSize) *MouseEvent {
 	if cb&CTRL_INDICATOR != 0 {
 		ans.Mods |= CTRL
 	}
-	ans.Cell.x = pixel_to_cell(ans.Pixel.x, int(screen_size.WidthPx), int(screen_size.CellWidth))
-	ans.Cell.y = pixel_to_cell(ans.Pixel.y, int(screen_size.HeightPx), int(screen_size.CellHeight))
+	ans.Cell.X = pixel_to_cell(ans.Pixel.X, int(screen_size.WidthPx), int(screen_size.CellWidth))
+	ans.Cell.Y = pixel_to_cell(ans.Pixel.Y, int(screen_size.HeightPx), int(screen_size.CellHeight))
 
 	return &ans
 }
diff --git a/tools/tui/loop/run.go b/tools/tui/loop/run.go
index 87624d353..a0f2e535b 100644
--- a/tools/tui/loop/run.go
+++ b/tools/tui/loop/run.go
@@ -86,9 +86,39 @@ func (self *Loop) handle_csi(raw []byte) error {
 	return nil
 }
 
+func is_click(a, b *MouseEvent) bool {
+	if a.Event_type != MOUSE_PRESS || b.Event_type != MOUSE_RELEASE {
+		return false
+	}
+	x := a.Cell.X - b.Cell.X
+	y := a.Cell.Y - b.Cell.Y
+	return x*x+y*y <= 4
+
+}
+
 func (self *Loop) handle_mouse_event(ev *MouseEvent) error {
 	if self.OnMouseEvent != nil {
-		return self.OnMouseEvent(ev)
+		err := self.OnMouseEvent(ev)
+		if err != nil {
+			return err
+		}
+		switch ev.Event_type {
+		case MOUSE_PRESS:
+			self.pending_mouse_events.WriteAllAndDiscardOld(*ev)
+		case MOUSE_RELEASE:
+			self.pending_mouse_events.WriteAllAndDiscardOld(*ev)
+			if self.pending_mouse_events.Len() > 1 {
+				events := self.pending_mouse_events.ReadAll()
+				if is_click(&events[len(events)-2], &events[len(events)-1]) {
+					e := events[len(events)-1]
+					e.Event_type = MOUSE_CLICK
+					err = self.OnMouseEvent(&e)
+					if err != nil {
+						return err
+					}
+				}
+			}
+		}
 	}
 	return nil
 }
@@ -243,6 +273,7 @@ func (self *Loop) run() (err error) {
 	}
 
 	self.keep_going = true
+	self.pending_mouse_events = utils.NewRingBuffer[MouseEvent](4)
 	tty_read_channel := make(chan []byte)
 	tty_write_channel := make(chan *write_msg, 1) // buffered so there is no race between initial queueing and startup of writer thread
 	write_done_channel := make(chan IdType)