diff --git a/kitty/boss.py b/kitty/boss.py
index 6efa02cb1..cb9bd238a 100644
--- a/kitty/boss.py
+++ b/kitty/boss.py
@@ -82,8 +82,8 @@ class Boss:
         load_shader_programs()
         self.tab_manager = TabManager(opts, args)
         self.tab_manager.init(startup_session)
+        self.activate_tab_at = self.tab_manager.activate_tab_at
         layout_sprite_map(cell_size.width, cell_size.height, render_cell_wrapper)
-        self.glfw_window.set_click_cursor(False)
 
     @property
     def current_tab_bar_height(self):
diff --git a/kitty/child-monitor.c b/kitty/child-monitor.c
index cfefd0776..3622599c6 100644
--- a/kitty/child-monitor.c
+++ b/kitty/child-monitor.c
@@ -31,7 +31,6 @@ extern int pthread_setname_np(const char *name);
 
 #define EXTRA_FDS 2
 
-extern GlobalState global_state;
 static void (*parse_func)(Screen*, PyObject*);
 
 typedef struct {
diff --git a/kitty/constants.py b/kitty/constants.py
index ea8ac18ba..16db315f9 100644
--- a/kitty/constants.py
+++ b/kitty/constants.py
@@ -11,7 +11,7 @@ from collections import namedtuple, defaultdict
 from .fast_data_types import (
     GLFW_KEY_LEFT_SHIFT, GLFW_KEY_RIGHT_SHIFT, GLFW_KEY_LEFT_ALT,
     GLFW_KEY_RIGHT_ALT, GLFW_KEY_LEFT_CONTROL, GLFW_KEY_RIGHT_CONTROL,
-    GLFW_KEY_LEFT_SUPER, GLFW_KEY_RIGHT_SUPER)
+    GLFW_KEY_LEFT_SUPER, GLFW_KEY_RIGHT_SUPER, set_boss as set_c_boss)
 
 appname = 'kitty'
 version = (0, 3, 0)
@@ -57,6 +57,7 @@ def get_boss():
 
 def set_boss(m):
     get_boss.boss = m
+    set_c_boss(m)
 
 
 def wakeup():
diff --git a/kitty/glfw.c b/kitty/glfw.c
index 39f782424..3a4570ced 100644
--- a/kitty/glfw.c
+++ b/kitty/glfw.c
@@ -16,7 +16,6 @@
 #error "glfw >= 3.2 required"
 #endif
 
-extern GlobalState global_state;
 #define MAX_WINDOWS 256
 
 #define CALLBACK(name, fmt, ...) \
@@ -63,12 +62,29 @@ key_callback(GLFWwindow UNUSED *w, int key, int scancode, int action, int mods)
     WINDOW_CALLBACK(key_callback, "iiii", key, scancode, action, mods);
 }
 
+extern void mouse_event(int, int);
+
 static void 
 mouse_button_callback(GLFWwindow *w, int button, int action, int mods) {
     if (!global_state.mouse_visible) { glfwSetInputMode(w, GLFW_CURSOR, GLFW_CURSOR_NORMAL); global_state.mouse_visible = true; } 
     double now = monotonic();
     global_state.last_mouse_activity_at = now;
-    WINDOW_CALLBACK(mouse_button_callback, "iii", button, action, mods);
+    if (button >= 0 && (unsigned int)button < sizeof(global_state.mouse_button_pressed)/sizeof(global_state.mouse_button_pressed)) {
+        global_state.mouse_button_pressed[button] = action == GLFW_PRESS ? true : false;
+        mouse_event(button, mods);
+    }
+    /* WINDOW_CALLBACK(mouse_button_callback, "iii", button, action, mods); */
+}
+
+static void 
+cursor_pos_callback(GLFWwindow *w, double x, double y) {
+    if (!global_state.mouse_visible) { glfwSetInputMode(w, GLFW_CURSOR, GLFW_CURSOR_NORMAL); global_state.mouse_visible = true; } 
+    double now = monotonic();
+    global_state.last_mouse_activity_at = now;
+    global_state.cursor_blink_zero_time = now;
+    global_state.mouse_x = x; global_state.mouse_y = y;
+    mouse_event(-1, 0);
+    /* WINDOW_CALLBACK(cursor_pos_callback, "dd", x, y); */
 }
 
 static void 
@@ -79,21 +95,6 @@ scroll_callback(GLFWwindow *w, double xoffset, double yoffset) {
     WINDOW_CALLBACK(scroll_callback, "dd", xoffset, yoffset);
 }
 
-static void 
-cursor_pos_callback(GLFWwindow *w, double x, double y) {
-    if (!global_state.mouse_visible) { glfwSetInputMode(w, GLFW_CURSOR, GLFW_CURSOR_NORMAL); global_state.mouse_visible = true; } 
-    double now = monotonic();
-    global_state.last_mouse_activity_at = now;
-    global_state.cursor_blink_zero_time = now;
-    WINDOW_CALLBACK(cursor_pos_callback, "dd", x, y);
-}
-
-void
-hide_mouse_cursor() {
-    glfwSetInputMode(the_window->window, GLFW_CURSOR, GLFW_CURSOR_HIDDEN);
-    global_state.mouse_visible = false;
-}
-
 static void 
 window_focus_callback(GLFWwindow UNUSED *w, int focused) {
     global_state.application_focused = focused ? true : false;
@@ -104,6 +105,11 @@ window_focus_callback(GLFWwindow UNUSED *w, int focused) {
 }
 // }}}
 
+void
+set_click_cursor(bool yes) {
+    glfwSetCursor(the_window->window, yes ? the_window->click_cursor : the_window->standard_cursor);
+}
+
 static PyObject*
 new(PyTypeObject *type, PyObject *args, PyObject UNUSED *kwds) {
     WindowWrapper *self;
@@ -121,6 +127,7 @@ new(PyTypeObject *type, PyObject *args, PyObject UNUSED *kwds) {
         self->standard_cursor = glfwCreateStandardCursor(GLFW_IBEAM_CURSOR);
         self->click_cursor = glfwCreateStandardCursor(GLFW_HAND_CURSOR);
         if (self->standard_cursor == NULL || self->click_cursor == NULL) { Py_CLEAR(self); PyErr_SetString(PyExc_ValueError, "Failed to create standard mouse cursors"); return NULL; }
+        set_click_cursor(false);
         glfwSetFramebufferSizeCallback(self->window, framebuffer_size_callback);
         glfwSetCharModsCallback(self->window, char_mods_callback);
         glfwSetKeyCallback(self->window, key_callback);
@@ -305,14 +312,6 @@ is_key_pressed(WindowWrapper *self, PyObject *args) {
     return ans;
 }
 
-static PyObject*
-set_click_cursor(WindowWrapper *self, PyObject *args) {
-    int c;
-    if (!PyArg_ParseTuple(args, "p", &c)) return NULL;
-    glfwSetCursor(self->window, c ? self->click_cursor : self->standard_cursor);
-    Py_RETURN_NONE;
-}
-
 static PyObject*
 set_clipboard_string(WindowWrapper *self, PyObject *args) {
     char *title;
@@ -424,7 +423,6 @@ static PyMethodDef methods[] = {
     MND(set_should_close, METH_VARARGS),
     MND(set_input_mode, METH_VARARGS),
     MND(is_key_pressed, METH_VARARGS),
-    MND(set_click_cursor, METH_VARARGS),
     MND(set_clipboard_string, METH_VARARGS),
     MND(make_context_current, METH_NOARGS),
     MND(window_id, METH_NOARGS),
diff --git a/kitty/mouse.c b/kitty/mouse.c
new file mode 100644
index 000000000..c8d1a6ba2
--- /dev/null
+++ b/kitty/mouse.c
@@ -0,0 +1,87 @@
+/*
+ * mouse.c
+ * Copyright (C) 2017 Kovid Goyal <kovid at kovidgoyal.net>
+ *
+ * Distributed under terms of the GPL3 license.
+ */
+
+#include "state.h"
+#include <GLFW/glfw3.h>
+
+extern void set_click_cursor(bool yes);
+static bool has_click_cursor = false;
+
+static inline bool
+contains_mouse(Window *w) {
+    WindowGeometry *g = &w->geometry;
+    double x = global_state.mouse_x, y = global_state.mouse_y;
+    return (w->visible && g->left <= x && x <= g->right && g->top <= y && y <= g->bottom) ? true : false;
+}
+
+static inline bool
+cell_for_pos(Window *w, unsigned int *x, unsigned int *y) {
+    unsigned int qx = (unsigned int)((double)global_state.mouse_x / global_state.cell_width);
+    unsigned int qy = (unsigned int)((double)global_state.mouse_x / global_state.cell_width);
+    bool ret = false;
+    Screen *screen = w->render_data.screen;
+    if (screen && qx <= screen->columns && qy <= screen->lines) {
+        *x = qx; *y = qy; ret = true;
+    }
+    return ret;
+}
+
+void 
+handle_move_event(Window *w, int UNUSED button, int UNUSED modifiers) {
+    unsigned int x, y;
+    if (cell_for_pos(w, &x, &y)) {
+        if (x != w->mouse_cell_x || y != w->mouse_cell_y) {
+            w->mouse_cell_x = x; w->mouse_cell_y = y;
+        }
+    }
+}
+
+void 
+handle_event(Window *w, int button, int modifiers) {
+    switch(button) {
+        case -1:
+            handle_move_event(w, button, modifiers);
+            break;
+        case GLFW_MOUSE_BUTTON_LEFT:  
+        case GLFW_MOUSE_BUTTON_RIGHT:
+        case GLFW_MOUSE_BUTTON_MIDDLE:
+        case GLFW_MOUSE_BUTTON_4:
+        case GLFW_MOUSE_BUTTON_5:
+            break;
+        default:
+            break;
+    }
+}
+
+void handle_tab_bar_mouse(int button, int UNUSED modifiers) {
+    if (button != GLFW_MOUSE_BUTTON_LEFT || !global_state.mouse_button_pressed[button]) return;
+    PyObject *ret = PyObject_CallMethod(global_state.boss, "activate_tab_at", "d", global_state.mouse_x);
+    if (ret == NULL) { PyErr_Print(); }
+    else Py_DECREF(ret);
+}
+
+void
+mouse_event(int button, int modifiers) {
+    bool old_has_click_cursor = has_click_cursor;
+    bool in_tab_bar = global_state.num_tabs > 1 && global_state.mouse_y >= global_state.viewport_height - global_state.cell_height ? true : false;
+    has_click_cursor = false;
+    if (in_tab_bar) { 
+        has_click_cursor = true;
+        handle_tab_bar_mouse(button, modifiers); 
+    } else {
+        Tab *t = global_state.tabs + global_state.active_tab;
+        for (size_t i = 0; i < t->num_windows; i++) {
+            if (contains_mouse(t->windows + i)) {
+                handle_event(t->windows + i, button, modifiers);
+                break;
+            }
+        }
+    }
+    if (has_click_cursor != old_has_click_cursor) {
+        set_click_cursor(has_click_cursor);
+    }
+}
diff --git a/kitty/screen.c b/kitty/screen.c
index 6a8829abe..cfb3a2bea 100644
--- a/kitty/screen.c
+++ b/kitty/screen.c
@@ -23,7 +23,6 @@
 #include "modes.h"
 #include "wcwidth9.h"
 
-extern GlobalState global_state;
 static const ScreenModes empty_modes = {0, .mDECAWM=true, .mDECTCEM=true, .mDECARM=true};
 static Selection EMPTY_SELECTION = {0};
 
diff --git a/kitty/shaders.c b/kitty/shaders.c
index 345ba4d90..9ed3a56cd 100644
--- a/kitty/shaders.c
+++ b/kitty/shaders.c
@@ -518,6 +518,8 @@ static void
 layout_sprite_map(unsigned int cell_width, unsigned int cell_height, PyObject *render_cell) {
     sprite_map.cell_width = MAX(1, cell_width);
     sprite_map.cell_height = MAX(1, cell_height);
+    global_state.cell_width = sprite_map.cell_width;
+    global_state.cell_height = sprite_map.cell_height;
     if (sprite_map.max_texture_size == 0) {
         glGetIntegerv(GL_MAX_TEXTURE_SIZE, &(sprite_map.max_texture_size));
         glGetIntegerv(GL_MAX_ARRAY_TEXTURE_LAYERS, &(sprite_map.max_array_texture_layers));
diff --git a/kitty/state.c b/kitty/state.c
index a1f315969..2101ba54c 100644
--- a/kitty/state.c
+++ b/kitty/state.c
@@ -142,17 +142,21 @@ PYWRAP1(set_tab_bar_render_data) {
 
 PYWRAP1(set_window_render_data) {
 #define A(name) &(d.name)
+#define B(name) &(g.name)
     unsigned int window_idx, tab_id;
-    ScreenRenderData d = {0};
-    PA("IIiffffO", &tab_id, &window_idx, A(vao_idx), A(xstart), A(ystart), A(dx), A(dy), A(screen));
+    static ScreenRenderData d = {0};
+    static WindowGeometry g = {0};
+    PA("IIiffffOIIII", &tab_id, &window_idx, A(vao_idx), A(xstart), A(ystart), A(dx), A(dy), A(screen), B(left), B(top), B(right), B(bottom));
 
     WITH_TAB(tab_id);
     Py_CLEAR(tab->windows[window_idx].render_data.screen);
     tab->windows[window_idx].render_data = d;
+    tab->windows[window_idx].geometry = g;
     Py_INCREF(tab->windows[window_idx].render_data.screen);
     END_WITH_TAB;
     Py_RETURN_NONE;
 #undef A
+#undef B
 }
 
 PYWRAP1(update_window_visibility) {
@@ -170,8 +174,16 @@ PYWRAP1(set_logical_dpi) {
     Py_RETURN_NONE;
 }
 
+PYWRAP1(set_boss) {
+    Py_CLEAR(global_state.boss);
+    global_state.boss = args;
+    Py_INCREF(global_state.boss);
+    Py_RETURN_NONE;
+}
+
 PYWRAP0(destroy_global_data) {
     Py_CLEAR(global_state.tab_bar_render_data.screen);
+    Py_CLEAR(global_state.boss);
     Py_RETURN_NONE;
 }
 
@@ -211,6 +223,7 @@ static PyMethodDef module_methods[] = {
     MW(set_tab_bar_render_data, METH_VARARGS),
     MW(set_window_render_data, METH_VARARGS),
     MW(update_window_visibility, METH_VARARGS),
+    MW(set_boss, METH_O),
     MW(destroy_global_data, METH_NOARGS),
 
     {NULL, NULL, 0, NULL}        /* Sentinel */
@@ -224,6 +237,7 @@ init_state(PyObject *module) {
     global_state.cursor_blink_zero_time = now;
     global_state.last_mouse_activity_at = now;
     global_state.mouse_visible = true;
+    global_state.cell_width = 1; global_state.cell_height = 1;
     if (PyModule_AddFunctions(module, module_methods) != 0) return false;
     return true;
 }
diff --git a/kitty/state.h b/kitty/state.h
index 331d7d249..584beaf5a 100644
--- a/kitty/state.h
+++ b/kitty/state.h
@@ -22,11 +22,17 @@ typedef struct {
     Screen *screen;
 } ScreenRenderData;
 
+typedef struct {
+    unsigned int left, top, right, bottom;
+} WindowGeometry;
+
 typedef struct {
     unsigned int id;
     bool visible;
     PyObject *title;
     ScreenRenderData render_data;
+    unsigned int mouse_cell_x, mouse_cell_y;
+    WindowGeometry geometry;
 } Window;
 
 typedef struct {
@@ -43,9 +49,14 @@ typedef struct {
     bool application_focused, mouse_visible;
     double cursor_blink_zero_time, last_mouse_activity_at;
     double logical_dpi_x, logical_dpi_y;
+    double mouse_x, mouse_y;
+    bool mouse_button_pressed[20];
     int viewport_width, viewport_height;
+    unsigned int cell_width, cell_height;
     PyObject *application_title;
+    PyObject *boss;
 } GlobalState;
+extern GlobalState global_state;
 
 #define EXTERNAL_FUNC(name, ret, ...) typedef ret (*name##_func)(__VA_ARGS__); extern name##_func name
 #define EXTERNAL_FUNC0(name, ret) typedef ret (*name##_func)(); extern name##_func name
diff --git a/kitty/window.py b/kitty/window.py
index da5a97ea1..2bcc61c9c 100644
--- a/kitty/window.py
+++ b/kitty/window.py
@@ -121,8 +121,8 @@ class Window:
             boss.child_monitor.resize_pty(self.id, *current_pty_size)
         else:
             sg = self.update_position(new_geometry)
-        set_window_render_data(self.tab_id, window_idx, self.vao_id, sg.xstart, sg.ystart, sg.dx, sg.dy, self.screen)
-        self.geometry = new_geometry
+        self.geometry = g = new_geometry
+        set_window_render_data(self.tab_id, window_idx, self.vao_id, sg.xstart, sg.ystart, sg.dx, sg.dy, self.screen, *g[:4])
 
     def contains(self, x, y):
         g = self.geometry