editor: Add support for cursor

Add support for setting, moving and rendering a cursor.

Signed-off-by: Jan Arne Petersen <jpetersen@openismus.com>

diff --git a/clients/editor.c b/clients/editor.c
index 03abab2..b375938 100644 (file)
--- a/clients/editor.c
+++ b/clients/editor.c
@@ -49,6 +49,7 @@ struct text_entry {
        struct window *window;
        char *text;
        int active;
+       uint32_t cursor;
        struct text_model *model;
        struct text_layout *layout;
 };
@@ -136,6 +137,68 @@ text_layout_draw(struct text_layout *layout, cairo_t *cr)
        cairo_restore(cr);
 }
 
+static void
+text_layout_extents(struct text_layout *layout, cairo_text_extents_t *extents)
+{
+       cairo_scaled_font_glyph_extents(layout->font,
+                                       layout->glyphs, layout->num_glyphs,
+                                       extents);
+}
+
+static int
+text_layout_xy_to_index(struct text_layout *layout, double x, double y)
+{
+       cairo_text_extents_t extents;
+       int i;
+
+       cairo_scaled_font_glyph_extents(layout->font,
+                                       layout->glyphs, layout->num_glyphs,
+                                       &extents);
+
+       for (i = 1; i < layout->num_glyphs; i++) {
+               if (layout->glyphs[i].x >= x) {
+                       return i - 1;
+               }
+       }
+
+       if (x >= layout->glyphs[layout->num_glyphs - 1].x && x < extents.width)
+               return layout->num_glyphs - 1;
+
+       return layout->num_glyphs;
+}
+
+static void
+text_layout_index_to_pos(struct text_layout *layout, uint32_t index, cairo_rectangle_t *pos)
+{
+       cairo_text_extents_t extents;
+
+       if (!pos)
+               return;
+
+       cairo_scaled_font_glyph_extents(layout->font,
+                                       layout->glyphs, layout->num_glyphs,
+                                       &extents);
+
+       if ((int)index >= layout->num_glyphs) {
+               pos->x = extents.x_advance;
+               pos->y = layout->num_glyphs ? layout->glyphs[layout->num_glyphs - 1].y : 0;
+               pos->width = 1;
+               pos->height = extents.height;
+               return;
+       }
+
+       pos->x = layout->glyphs[index].x;
+       pos->y = layout->glyphs[index].y;
+       pos->width = (int)index < layout->num_glyphs - 1 ? layout->glyphs[index + 1].x : extents.x_advance - pos->x;
+       pos->height = extents.height;
+}
+
+static void
+text_layout_get_cursor_pos(struct text_layout *layout, int index, cairo_rectangle_t *pos)
+{
+       text_layout_index_to_pos(layout, index, pos);
+       pos->width = 1;
+}
 
 static void text_entry_redraw_handler(struct widget *widget, void *data);
 static void text_entry_button_handler(struct widget *widget,
@@ -248,6 +311,7 @@ text_entry_create(struct editor *editor, const char *text)
        entry->window = editor->window;
        entry->text = strdup(text);
        entry->active = 0;
+       entry->cursor = strlen(text);
        entry->model = text_model_factory_create_text_model(editor->text_model_factory);
        text_model_add_listener(entry->model, &text_model_listener, entry);
 
@@ -345,6 +409,30 @@ text_entry_deactivate(struct text_entry *entry,
 }
 
 static void
+text_entry_set_cursor_position(struct text_entry *entry,
+                              int32_t x, int32_t y)
+{
+       entry->cursor = text_layout_xy_to_index(entry->layout, x, y);
+
+       widget_schedule_redraw(entry->widget);
+}
+
+static void
+text_entry_draw_cursor(struct text_entry *entry, cairo_t *cr)
+{
+       cairo_text_extents_t extents;
+       cairo_rectangle_t cursor_pos;
+
+       text_layout_extents(entry->layout, &extents);
+       text_layout_get_cursor_pos(entry->layout, entry->cursor, &cursor_pos);
+
+       cairo_set_line_width(cr, 1.0);
+       cairo_move_to(cr, cursor_pos.x, extents.y_bearing + extents.height + 2);
+       cairo_line_to(cr, cursor_pos.x, extents.y_bearing - 2);
+       cairo_stroke(cr);
+}
+
+static void
 text_entry_redraw_handler(struct widget *widget, void *data)
 {
        struct text_entry *entry = data;
@@ -381,6 +469,9 @@ text_entry_redraw_handler(struct widget *widget, void *data)
 
        cairo_translate(cr, 10, allocation.height / 2);
        text_layout_draw(entry->layout, cr);
+
+       text_entry_draw_cursor(entry, cr);
+
        cairo_pop_group_to_source(cr);
        cairo_paint(cr);
 
@@ -395,11 +486,20 @@ text_entry_button_handler(struct widget *widget,
                          enum wl_pointer_button_state state, void *data)
 {
        struct text_entry *entry = data;
+       struct rectangle allocation;
+       int32_t x, y;
+
+       widget_get_allocation(entry->widget, &allocation);
+       input_get_position(input, &x, &y);
 
        if (button != BTN_LEFT) {
                return;
        }
 
+       text_entry_set_cursor_position(entry, 
+                                      x - allocation.x,
+                                      y - allocation.y);
+
        if (state == WL_POINTER_BUTTON_STATE_PRESSED) {
                struct wl_seat *seat = input_get_seat(input);