Compute the layout for the buttons

3 files changed, 74 insertions, 40 deletions

diff --git a/src/comet.c b/src/comet.c
index df5ffe4..21bad7a 100644
--- a/src/comet.c
+++ b/src/comet.c
@@ -71,7 +71,7 @@ int main(int argc, char **argv)
     Button *btn = button_create("long button", false);
     state_add_button(state, btn);
 
-    draw_set_buttons(draw, state->btns);
+    draw_compute_layout(draw, state->btns, window_get_context(win));
 
     connect_attach_state(con, state);
     connect_attach_source(con);
diff --git a/src/draw.c b/src/draw.c
index 0122ab4..8a2a6bd 100644
--- a/src/draw.c
+++ b/src/draw.c
@@ -12,6 +12,20 @@
 // (this will also work for animations in the future)
 // or use some flags to trigger drawing
 
+typedef struct {
+    Button *btn;
+    int x, y;
+    int width, height;
+    int text_w, text_h;
+    PangoLayout *pl;
+} Layout;
+
+static void layout_destroy(Layout *layout)
+{
+    g_object_unref(layout->pl);
+    g_free(layout);
+}
+
 Drawable *draw_create(const char *font, int height, int left_pad, int right_pad, int top_pad, double alpha)
 {
     Drawable *draw = g_malloc(sizeof(Drawable));
@@ -28,6 +42,8 @@ Drawable *draw_create(const char *font, int height, int left_pad, int right_pad,
     draw->alpha = alpha;
     g_assert(alpha >= 0 && alpha <= 1);
 
+    draw->layouts = NULL;
+
     log_debug("Draw context created [height=%d, left_pad=%d, right_pad=%d, top_pad=%d, alpha=%.2lf]", height, left_pad, right_pad, top_pad, alpha);
 
     return draw;
@@ -72,56 +88,33 @@ void draw_paint(Drawable *draw, Window *win)
     int line_w = 1 * scale;
     cairo_set_line_width(cr, line_w);
 
-    int bx = 0;
-
-    for (GList *it = draw->btns; it; it = it->next) {
-        Button *btn = it->data;
-
-        PangoLayout *layout = pango_cairo_create_layout(cr);
-        pango_layout_set_font_description(layout, draw->desc);
-
-        int bwidth = height, bheight = height;
-
-        pango_layout_set_text(layout, btn->text, -1);
-        pango_layout_set_alignment(layout, PANGO_ALIGN_CENTER);
+    for (GList *it = draw->layouts; it; it = it->next) {
+        Layout *layout = it->data;
 
-        int text_w, text_h;
-        pango_layout_get_pixel_size(layout, &text_w, &text_h);
-        text_w = ceil(text_w / scale);
-        text_h = ceil(text_h / scale);
-
-        if (!btn->fixed_size) {
-            bwidth = text_w + 2 * radius;
-        }
-
-        int text_x = bx + (bwidth / 2) - (text_w / 2);
-        int text_y = (bheight / 2) - (text_h / 2);
+        int text_x = layout->x + (layout->width / 2) - (layout->text_w / 2);
+        int text_y = layout->y + (layout->height / 2) - (layout->text_h / 2);
 
         // purple
         cairo_set_source_rgba(cr, 0.502, 0.168, 0.886, 1);
         cairo_new_sub_path(cr);
-        cairo_arc(cr, bx + radius, radius, radius, 90 * degree, 270 * degree);
-        cairo_arc(cr, bx + bwidth - radius, radius, radius, 270 * degree, 450 * degree);
+        cairo_arc(cr, layout->x + radius, layout->y + radius, radius, 90 * degree, 270 * degree);
+        cairo_arc(cr, layout->x + layout->width - radius, layout->y + radius, radius, 270 * degree, 450 * degree);
         cairo_close_path(cr);
         cairo_fill(cr);
 
         cairo_set_source_rgba(cr, 0.8, 0.8, 0.8, 1);
         cairo_new_sub_path(cr);
-        cairo_arc(cr, bx + radius, radius, radius - line_w , 90 * degree, 270 * degree);
-        cairo_arc(cr, bx + bwidth - radius, radius, radius - line_w, 270 * degree, 450 * degree);
+        cairo_arc(cr, layout->x + radius, layout->y + radius, radius - line_w , 90 * degree, 270 * degree);
+        cairo_arc(cr, layout->x + layout->width - radius, layout->y + radius, radius - line_w, 270 * degree, 450 * degree);
         cairo_close_path(cr);
         cairo_stroke(cr);
 
         cairo_set_source_rgb(cr, 0.8, 0.8, 0.8);
         cairo_move_to(cr, text_x, text_y);
 
-        pango_cairo_update_layout(cr, layout);
-        pango_cairo_show_layout(cr, layout);
+        pango_cairo_update_layout(cr, layout->pl);
+        pango_cairo_show_layout(cr, layout->pl);
 
-        g_object_unref(layout);
-
-        int sep = 10 * scale;
-        bx += height + line_w * 2 + sep;
     }
 
     cairo_destroy(cr);
@@ -134,13 +127,55 @@ void draw_paint(Drawable *draw, Window *win)
     cairo_surface_destroy(surface);
 }
 
-void draw_set_buttons(Drawable *draw, GList *btns)
+void draw_compute_layout(Drawable *draw, GList *btns, cairo_t *cr)
 {
-    draw->btns = btns;
+    g_list_free_full(draw->layouts, (GDestroyNotify)layout_destroy);
+    draw->layouts = NULL;
+
+    // FIXME: Does not work for scale != 1
+    //double scale = window_get_scale(win);
+    double scale = 1;
+
+    int x = 0;
+    int height = round(draw->height * scale);
+    int radius = height / 2;
+
+    for (GList *it = btns; it; it = it->next) {
+        Button *btn = it->data;
+
+        Layout *layout = g_malloc(sizeof(Layout));
+        layout->btn = btn;
+
+        layout->x = x;
+        layout->y = 0;
+
+        layout->pl = pango_cairo_create_layout(cr);
+        pango_layout_set_font_description(layout->pl, draw->desc);
+        pango_layout_set_text(layout->pl, btn->text, -1);
+        pango_layout_set_alignment(layout->pl, PANGO_ALIGN_CENTER);
+
+        int text_w, text_h;
+        pango_layout_get_pixel_size(layout->pl, &text_w, &text_h);
+
+        layout->text_w = ceil(text_w / scale);
+        layout->text_h = ceil(text_h / scale);
+
+        layout->width = btn->fixed_size ? height : layout->text_w + 2 * radius;
+        layout->height = height;
+
+        draw->layouts = g_list_append(draw->layouts, layout);
+
+        int sep = 10 * scale;
+        int line_w = 1 * scale;
+        x += height + line_w * 2 + sep;
+    }
+
+    log_debug("Updated layouts");
 }
 
 void draw_destroy(Drawable *draw)
 {
+    g_list_free_full(draw->layouts, (GDestroyNotify)layout_destroy);
     pango_font_description_free(draw->desc);
     g_free(draw);
 }
diff --git a/src/draw.h b/src/draw.h
index 481c080..c4f88e6 100644
--- a/src/draw.h
+++ b/src/draw.h
@@ -3,25 +3,24 @@
 
 #include <glib.h>
 #include <pango/pango-font.h>
-#include <pango/pango-types.h>
 
 #include "window.h"
 
 typedef struct Drawable Drawable;
 
 struct Drawable {
-    PangoFontDescription *desc;
     int height;
     int left_pad;
     int right_pad;
     int top_pad;
     double alpha;
-    GList *btns;
+    GList *layouts;
+    PangoFontDescription *desc;
 };
 
 Drawable *draw_create(const char *font, int height, int left_pad, int right_pad, int top_pad, double alpha);
 
-void draw_set_buttons(Drawable *draw, GList *btns);
+void draw_compute_layout(Drawable *draw, GList *btns, cairo_t *cr);
 
 void draw_paint(Drawable *draw, Window *win);