Implement select-by-rectangle when holding down Ctrl+Alt

Fixes #225

kitty/mouse.c

@@ -107,11 +107,11 @@ cell_for_pos(Window *w, unsigned int *x, unsigned int *y) {
 #define HANDLER(name) static inline void name(Window UNUSED *w, int UNUSED button, int UNUSED modifiers, unsigned int UNUSED window_idx)
 
 static inline void
-update_drag(bool from_button, Window *w, bool is_release) {
+update_drag(bool from_button, Window *w, bool is_release, int modifiers) {
     Screen *screen = w->render_data.screen;
     if (from_button) {
         if (is_release) screen_update_selection(screen, w->mouse_cell_x, w->mouse_cell_y, true);
-        else screen_start_selection(screen, w->mouse_cell_x, w->mouse_cell_y);
+        else screen_start_selection(screen, w->mouse_cell_x, w->mouse_cell_y, modifiers == (GLFW_MOD_CONTROL | GLFW_MOD_ALT));
     } else if (screen->selection.in_progress) {
         screen_update_selection(screen, w->mouse_cell_x, w->mouse_cell_y, false);
         call_boss(set_primary_selection, NULL);
@@ -130,7 +130,7 @@ drag_scroll(Window *w, OSWindow *frame) {
         Screen *screen = w->render_data.screen;
         if (screen->linebuf == screen->main_linebuf) {
             screen_history_scroll(screen, SCROLL_LINE, upwards);
-            update_drag(false, w, false);
+            update_drag(false, w, false, 0);
             frame->last_mouse_activity_at = monotonic();
             if (mouse_cursor_shape != ARROW) {
                 mouse_cursor_shape = ARROW;
@@ -199,7 +199,7 @@ HANDLER(handle_move_event) {
         if (screen->selection.in_progress && button == GLFW_MOUSE_BUTTON_LEFT) {
             double now = monotonic();
             if ((now - w->last_drag_scroll_at) >= 0.02 || mouse_cell_changed) {
-                update_drag(false, w, false);
+                update_drag(false, w, false, 0);
                 w->last_drag_scroll_at = monotonic();
             }
         }
@@ -226,7 +226,7 @@ multi_click(Window *w, unsigned int count) {
             break;
     }
     if (found_selection) {
-        screen_start_selection(screen, start, w->mouse_cell_y);
+        screen_start_selection(screen, start, w->mouse_cell_y, false);
         screen_update_selection(screen, end, w->mouse_cell_y, true);
         call_boss(set_primary_selection, NULL);
     }
@@ -272,7 +272,7 @@ HANDLER(handle_button_event) {
     if (handle_in_kitty) {
         switch(button) {
             case GLFW_MOUSE_BUTTON_LEFT:
-                update_drag(true, w, is_release);
+                update_drag(true, w, is_release, modifiers);
                 if (is_release) {
                     if (modifiers == (int)OPT(open_url_modifiers)) {
                         open_url(w);

kitty/screen.c

@@ -1226,15 +1226,36 @@ visual_line_(Screen *self, index_type y) {
     return self->linebuf->line;
 }
 
+#define iterate_over_rectangle(start, end) { \
+    index_type min_y = MIN(start->y, end->y), max_y = MAX(start->y, end->y); \
+    index_type min_x = MIN(start->x, end->x), max_x = MAX(start->x, end->x); \
+    for (index_type y = min_y; y <= max_y; y++) { \
+        Line *line = visual_line_(self, y); \
+        index_type xlimit = xlimit_for_line(line); \
+        xlimit = MIN(max_x + 1, xlimit); \
+        index_type x_start = min_x; \
+
+#define iterate_over_region(start, end) { \
+    for (index_type y = start->y; y <= end->y; y++) { \
+        Line *line = visual_line_(self, y); \
+        index_type xlimit = xlimit_for_line(line); \
+        if (y == end->y) xlimit = MIN(end->x + 1, xlimit); \
+        index_type x_start = y == start->y ? start->x : 0;
+ 
+
 static inline void
-apply_selection(Screen *self, uint8_t *data, SelectionBoundary *start, SelectionBoundary *end, uint8_t set_mask) {
+apply_selection(Screen *self, uint8_t *data, SelectionBoundary *start, SelectionBoundary *end, uint8_t set_mask, bool rectangle_select) {
     if (is_selection_empty(self, start->x, start->y, end->x, end->y)) return; 
-    for (index_type y = start->y; y <= end->y; y++) {
+    if (rectangle_select) {
-        Line *line = visual_line_(self, y);
+        iterate_over_rectangle(start, end)
-        index_type xlimit = xlimit_for_line(line);
+            uint8_t *line_start = data + self->columns * y;
-        if (y == end->y) xlimit = MIN(end->x + 1, xlimit);
+            for (index_type x = x_start; x < xlimit; x++) line_start[x] |= set_mask;
-        uint8_t *line_start = data + self->columns * y;
+        }}
-        for (index_type x = (y == start->y ? start->x : 0); x < xlimit; x++) line_start[x] |= set_mask;
+    } else {
+        iterate_over_region(start, end)
+            uint8_t *line_start = data + self->columns * y;
+            for (index_type x = x_start; x < xlimit; x++) line_start[x] |= set_mask;
+        }}
     }
 
 }
@@ -1245,26 +1266,30 @@ screen_apply_selection(Screen *self, void *address, size_t size) {
     self->last_selection_scrolled_by = self->scrolled_by;
     self->selection_updated_once = true;
     selection_limits_(selection, &self->last_rendered_selection_start, &self->last_rendered_selection_end);
-    apply_selection(self, address, &self->last_rendered_selection_start, &self->last_rendered_selection_end, 1);
+    apply_selection(self, address, &self->last_rendered_selection_start, &self->last_rendered_selection_end, 1, self->rectangle_select);
     selection_limits_(url_range, &self->last_rendered_url_start, &self->last_rendered_url_end);
-    apply_selection(self, address, &self->last_rendered_url_start, &self->last_rendered_url_end, 2);
+    apply_selection(self, address, &self->last_rendered_url_start, &self->last_rendered_url_end, 2, false);
 }
 
 static inline PyObject*
-text_for_range(Screen *self, SelectionBoundary start, SelectionBoundary end) {
+text_for_range(Screen *self, SelectionBoundary start, SelectionBoundary end, bool rectangle_select, bool insert_newlines) {
-    Py_ssize_t i = 0, num_of_lines = end.y - start.y + 1;
+    int num_of_lines = end.y - start.y + 1, i = 0;
     PyObject *ans = PyTuple_New(num_of_lines);
     if (ans == NULL) return PyErr_NoMemory();
-    for (index_type y = start.y; y <= end.y; y++, i++) {
+#define action \
-        Line *line = visual_line_(self, y);
+        char leading_char = (i > 0 && insert_newlines && !line->continued) ? '\n' : 0; \
-        index_type xlimit = xlimit_for_line(line);
+        PyObject *text = unicode_in_range(line, x_start, xlimit, true, leading_char); \
-        if (y == end.y) xlimit = MIN(end.x + 1, xlimit);
+        if (text == NULL) { Py_DECREF(ans); return PyErr_NoMemory(); } \
-        index_type xstart = (y == start.y ? start.x : 0);
+        PyTuple_SET_ITEM(ans, i++, text);
-        char leading_char = i > 0 && !line->continued ? '\n' : 0;
+
-        PyObject *text = unicode_in_range(line, xstart, xlimit, true, leading_char);
+    if (rectangle_select) {
-        if (text == NULL) { Py_DECREF(ans); return PyErr_NoMemory(); }
+        iterate_over_rectangle((&start), (&end))
-        PyTuple_SET_ITEM(ans, i, text);
+            action
-    }
+    }}} else {
+        iterate_over_region((&start), (&end))
+            action
+    }}}
+#undef action
     return ans;
 }
 
@@ -1273,7 +1298,7 @@ screen_open_url(Screen *self) {
     SelectionBoundary start, end;
     selection_limits_(url_range, &start, &end);
     if (is_selection_empty(self, start.x, start.y, end.x, end.y)) return false;
-    PyObject *text = text_for_range(self, start, end);
+    PyObject *text = text_for_range(self, start, end, false, false);
     if (text) { call_boss(open_url_lines, "(O)", text); Py_CLEAR(text); }
     else PyErr_Print();
     return true;
@@ -1435,7 +1460,7 @@ text_for_selection(Screen *self) {
     SelectionBoundary start, end;
     selection_limits_(selection, &start, &end);
     if (is_selection_empty(self, start.x, start.y, end.x, end.y)) return PyTuple_New(0);
-    return text_for_range(self, start, end);
+    return text_for_range(self, start, end, self->rectangle_select, true);
 }
  
 bool
@@ -1524,7 +1549,8 @@ screen_is_selection_dirty(Screen *self) {
 }
 
 void
-screen_start_selection(Screen *self, index_type x, index_type y) {
+screen_start_selection(Screen *self, index_type x, index_type y, bool rectangle_select) {
+    self->rectangle_select = rectangle_select;
 #define A(attr, val) self->selection.attr = val;
     A(start_x, x); A(end_x, x); A(start_y, y); A(end_y, y); A(start_scrolled_by, self->scrolled_by); A(end_scrolled_by, self->scrolled_by); A(in_progress, true);
 #undef A

kitty/screen.h

@@ -36,7 +36,7 @@ typedef struct {
     Selection selection;
     SelectionBoundary last_rendered_selection_start, last_rendered_selection_end, last_rendered_url_start, last_rendered_url_end;
     Selection url_range;
-    bool use_latin1, selection_updated_once, is_dirty, scroll_changed;
+    bool use_latin1, selection_updated_once, is_dirty, scroll_changed, rectangle_select;
     Cursor *cursor;
     SavepointBuffer main_savepoints, alt_savepoints;
     PyObject *callbacks, *test_child;
@@ -125,7 +125,7 @@ void screen_update_cell_data(Screen *self, void *address, size_t sz);
 bool screen_is_cursor_visible(Screen *self);
 bool screen_selection_range_for_line(Screen *self, index_type y, index_type *start, index_type *end);
 bool screen_selection_range_for_word(Screen *self, index_type x, index_type y, index_type *start, index_type *end);
-void screen_start_selection(Screen *self, index_type x, index_type y);
+void screen_start_selection(Screen *self, index_type x, index_type y, bool);
 void screen_update_selection(Screen *self, index_type x, index_type y, bool ended);
 bool screen_history_scroll(Screen *self, int amt, bool upwards);
 Line* screen_visual_line(Screen *self, index_type y);