Rewrite layout calculation

3 files changed, 118 insertions, 133 deletions

diff --git a/src/comet.c b/src/comet.c
index 5bcd9ac..b47c078 100644
--- a/src/comet.c
+++ b/src/comet.c
@@ -286,6 +286,7 @@ int main(int argc, char **argv)
     Color background_all = { 0.3, 0.3, 0.3, 1 };
     Drawer *draw = draw_create("Hack 13 Bold", height, x_padding, x_padding, y_padding);
     draw_set_background(draw, background_all);
+    draw_set_separator(draw, 10);
 
     State *state = state_create(win, draw);
 
@@ -353,7 +354,8 @@ int main(int argc, char **argv)
         State *state;
     } menu_ctx = { (gpointer)group, {"", ""}, NULL, state };
 
-    Button *menu = button_simple_create(PANGO_ALIGN_CENTER, color);
+    // XXX: If the alignment of the group and menu button are not equal something strange happens
+    Button *menu = button_simple_create(PANGO_ALIGN_LEFT, color);
     button_simple_set_text(menu, g_strdup(menu_ctx.strings[0]), text_color);
     button_simple_set_action(menu, menu_action, &menu_ctx);
 
diff --git a/src/draw.c b/src/draw.c
index 13e9058..abdbb8e 100644
--- a/src/draw.c
+++ b/src/draw.c
@@ -8,16 +8,9 @@
 #include "button.h"
 #include "log.h"
 
-static void layout_destroy(Layout *layout)
-{
-    if (layout->pl != NULL) g_object_unref(layout->pl);
-    g_list_free_full(layout->children, (GDestroyNotify)layout_destroy);
-    g_free(layout);
-}
-
 Drawer *draw_create(const char *font, int height, int left_pad, int right_pad, int top_pad)
 {
-    Drawer *draw = g_malloc(sizeof(Drawer));
+    Drawer *draw = g_malloc0(sizeof(Drawer));
     g_assert_nonnull(draw);
 
     log_debug("Pango loading font description '%s'", font);
@@ -29,8 +22,6 @@ Drawer *draw_create(const char *font, int height, int left_pad, int right_pad, i
     draw->right_pad = right_pad;
     draw->top_pad = top_pad;
 
-    draw->layouts = NULL;
-
     log_debug("Draw context created [height=%d, left_pad=%d, right_pad=%d, top_pad=%d]",
         height, left_pad, right_pad, top_pad);
 
@@ -38,13 +29,10 @@ Drawer *draw_create(const char *font, int height, int left_pad, int right_pad, i
 }
 
 // TODO: Remove this
-static void compute_width(Drawer *draw, Window *win, int *width, int *height)
+static void compute_width(Drawer *draw, Window *win)
 {
     int screen_width = win->con->screen_size->width;
-    int screen_height = win->con->screen_size->height;
-
-    *width  = round(screen_width - draw->right_pad - draw->left_pad);
-    *height = round(draw->height);
+    draw->width = round(screen_width - draw->right_pad - draw->left_pad);
 }
 
 static void paint_button(cairo_t *cr, const Layout *layout)
@@ -139,10 +127,10 @@ static void paint_button_list(cairo_t *cr, GList *layouts)
 
 void draw_paint(Drawer *draw, Window *win)
 {
-    int width, height;
-    compute_width(draw, win, &width, &height);
+    compute_width(draw, win);
 
-    cairo_surface_t *surface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, width, height);
+    // Back buffering
+    cairo_surface_t *surface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, draw->width, draw->height);
 
     cairo_t *cr = cairo_create(surface);
     cairo_set_fill_rule(cr, CAIRO_FILL_RULE_EVEN_ODD);
@@ -157,13 +145,30 @@ void draw_paint(Drawer *draw, Window *win)
     cairo_destroy(cr);
 
     window_move(win, draw->left_pad, draw->top_pad);
-    window_resize(win, width, draw->height);
+    window_resize(win, draw->width, draw->height);
 
-    window_paint_surface(win, surface, width, height);
+    window_paint_surface(win, surface, draw->width, draw->height);
     cairo_surface_destroy(surface);
 }
 
-static void layout_set_text(Layout *layout, PangoFontDescription *desc, int height, int radius)
+static void layout_destroy(Layout *layout)
+{
+    if (layout->pl != NULL) g_object_unref(layout->pl);
+    g_list_free_full(layout->children, (GDestroyNotify)layout_destroy);
+    g_free(layout);
+}
+
+static void layout_adjust(GList *start, GList *end, int off)
+{
+    // NOTE: end must be present in the list or segfault
+    for (GList *it = start; it != end; it = it->next) {
+        Layout *layout = it->data;
+        layout->x += off;
+        layout_adjust(layout->children, NULL, off);
+    }
+}
+
+static void layout_set_text(Layout *layout, PangoFontDescription *desc, int height)
 {
     g_assert(layout->btn->simple);
 
@@ -172,167 +177,132 @@ static void layout_set_text(Layout *layout, PangoFontDescription *desc, int heig
     pango_layout_set_font_description(layout->pl, desc);
     pango_layout_set_text(layout->pl, 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);
-    layout->text_h = ceil(text_h);
+    pango_layout_get_pixel_size(layout->pl, &layout->text_w, &layout->text_h);
 
     // If there is only one glyph the button should be round
     size_t text_l = g_utf8_strlen(text, -1);
 
-    layout->width = text_l == 1 ? height : layout->text_w + 2 * radius;
+    layout->width = text_l == 1 ? height : layout->text_w + height;
     layout->height = height;
 }
 
-void draw_compute_layout(Drawer *draw, Window *win, GList *btns)
+static GList *compute_group_layout(Drawer *draw, Window *win, GList *btns, int bx, bool root)
 {
-    g_list_free_full(draw->layouts, (GDestroyNotify)layout_destroy);
-    draw->layouts = NULL;
-
-    int width, height;
-    compute_width(draw, win, &width, &height);
-
-    Button *prev = NULL;
-
-    int x = 0;
-    int radius = height / 2;
-    int sep = 10;
-
-    GList *layout_start[3] = { NULL };
-    int layout_end[3] = { 0 };
-
+    GList *layouts = NULL;
     for (GList *it = btns; it; it = it->next) {
         Button *btn = it->data;
 
-        Layout *layout = g_malloc(sizeof(Layout));
-        layout->btn = btn;
-        layout->children = NULL;
-
-        if (prev != NULL && prev->align == btn->align) x += sep;
+        Layout *layout = g_malloc0(sizeof(Layout));
+        layouts = g_list_prepend(layouts, layout);
 
+        layout->btn = btn;
         layout->line_w = btn->line_width;
         layout->x_pad = btn->x_pad;
         layout->y_pad = btn->y_pad;
-
-        layout->x = x;
+        layout->x = bx;
         layout->y = 0;
 
-        draw->layouts = g_list_prepend(draw->layouts, layout);
-
-        if (prev == NULL || prev->align != btn->align) {
-            layout_start[btn->align] = draw->layouts;
-        }
-
+        // TODO: Allow nested groups
         if (!btn->simple) {
             ButtonGroup *group = CAST(btn, ButtonGroup);
             g_assert_nonnull(group->children);
 
             // If there is only one child treat a group like a single button
             if (group->children->next == NULL) {
-                Button *child = group->children->data;
-                g_assert_true(child->simple);
-                layout->btn = child;
+                layout->btn = btn = group->children->data;
+                g_assert_true(btn->simple);
             } else {
-                for (GList *it = group->children; it; it = it->next) {
-                    Button *btn = it->data;
-                    // Nested groups are not allowed
-                    g_assert_true(btn->simple);
-
-                    Layout *child = g_malloc(sizeof(Layout));
-                    child->btn = btn;
-                    child->children = NULL;
-                    child->line_w = btn->line_width;
-
-                    child->x_pad = btn->x_pad;
-                    child->y_pad = btn->y_pad;
-
-                    child->x = x;
-                    child->y = 0;
-
-                    child->pl = pango_cairo_create_layout(window_get_context(win));
-                    layout_set_text(child, draw->desc, height, radius);
-                    child->width += child->line_w;
-
-                    layout->children = g_list_prepend(layout->children, child);
-
-                    x += child->width;
-                    if (it->next != NULL) x += sep;
-                }
-
-                layout->pl = NULL;
-                layout->width = x - layout->x;
-                layout->height = height;
+                layout->children = compute_group_layout(draw, win, group->children, bx, false);
+                g_assert_nonnull(layout->children);
 
-                // Otherwise button_action_find will not work!
-                layout->children = g_list_reverse(layout->children);
+                Layout *last = g_list_last(layout->children)->data;
+                layout->width = last->x + last->width - bx;
+                layout->height = draw->height;
 
                 // FIXME: Temporary solution to make the antialiasing (or the circles not overlapping correctly) problem less noticeable
-
-                bool fix_left = CAST(g_list_first(group->children)->data, Button)->x_pad == 0;
-                bool fix_right = CAST(g_list_last(group->children)->data, Button)->x_pad == 0;
-
+                bool fix_left = CAST(layout->children->data, Layout)->x_pad == 0;
                 if (fix_left) {
                     layout->x += 1;
                     layout->width -= 1;
                 }
-                if (fix_right) layout->width -= 1;
+
+                bool fix_right = last->x_pad == 0;
+                if (fix_right)
+                    layout->width -= 1;
             }
         }
 
-        if (layout->btn->simple) {
+        // NOTE: This check is only apparently redundant because it handles the case where there
+        //       there is only a single children in a group
+        if (btn->simple) {
             layout->pl = pango_cairo_create_layout(window_get_context(win));
-            layout_set_text(layout, draw->desc, height, radius);
-
-            // TODO: make it work for groups
-            if (btn->anim != NULL && btn->anim->layout_func != NULL) {
-                if (btn->anim->start == 0) {
-                    btn->anim->start = g_get_monotonic_time();
-                    log_debug("Starting animation [type=%d, start=%ld, duration=%ld, button=%p]",
-                        btn->anim->type, btn->anim->start, btn->anim->duration, btn);
-                }
+            layout_set_text(layout, draw->desc, draw->height);
+        }
 
-                if (!btn->anim->layout_func(btn->anim, layout))
-                    btn->anim->layout_func = NULL;
+        // NOTE: We add half a line width on both sides
+        layout->width += layout->line_w;
+
+        if (btn->anim != NULL && btn->anim->layout_func != NULL) {
+            if (btn->anim->start == 0) {
+                btn->anim->start = g_get_monotonic_time();
+                log_debug("Starting animation [type=%d, start=%ld, duration=%ld, button=%p]",
+                    btn->anim->type, btn->anim->start, btn->anim->duration, btn);
             }
 
-            layout->width += layout->line_w;
-            x += layout->width;
+            if (!btn->anim->layout_func(btn->anim, layout))
+                btn->anim->layout_func = NULL;
+        }
+
+        bx += layout->width;
+        if (root) {
+            draw->layout_bx[btn->align] = bx;
+            draw->layout_end[btn->align] = layouts;
         }
 
-        prev = btn;
-        layout_end[btn->align] = x;
+        if (it->next != NULL && (!root || CAST(it->next->data, Button)->align == btn->align))
+            bx += draw->sep;
     }
 
-    draw->layouts = g_list_reverse(draw->layouts);
+    // Otherwise button_action_find will not work!
+    layouts = g_list_reverse(layouts);
+    return layouts;
+}
+
+void draw_compute_layout(Drawer *draw, Window *win, GList *btns)
+{
+    compute_width(draw, win);
+
+    g_list_free_full(draw->layouts, (GDestroyNotify)layout_destroy);
+    draw->layouts = compute_group_layout(draw, win, btns, 0, true);
 
-    int layout_width[3] = {
-        layout_end[PANGO_ALIGN_LEFT],
-        layout_end[PANGO_ALIGN_CENTER] - layout_end[PANGO_ALIGN_LEFT],
-        layout_end[PANGO_ALIGN_RIGHT] - MAX(layout_end[PANGO_ALIGN_CENTER], layout_end[PANGO_ALIGN_LEFT]),
-    };
+    draw->layout_width[PANGO_ALIGN_LEFT] = draw->layout_bx[PANGO_ALIGN_LEFT];
+    draw->layout_width[PANGO_ALIGN_CENTER] = draw->layout_bx[PANGO_ALIGN_CENTER] - draw->layout_bx[PANGO_ALIGN_LEFT];
+    draw->layout_width[PANGO_ALIGN_RIGHT] = draw->layout_bx[PANGO_ALIGN_RIGHT] - MAX(draw->layout_bx[PANGO_ALIGN_CENTER], draw->layout_bx[PANGO_ALIGN_LEFT]);
 
-    if (layout_end[PANGO_ALIGN_RIGHT] > width) {
-        log_error("Layout is bigger than the window (%d vs %d)", layout_end[PANGO_ALIGN_RIGHT], width);
+    if (draw->layout_bx[PANGO_ALIGN_RIGHT] > draw->width) {
+        log_error("Layout is bigger than the window (%d vs %d)", draw->layout_bx[PANGO_ALIGN_RIGHT], draw->width);
     }
 
-    int center = round(width / 2);
-    int center_off = center - round(layout_width[PANGO_ALIGN_CENTER] / 2) - layout_end[PANGO_ALIGN_LEFT];
-    log_debug("Aligning center layout [center=%d, off=%d]", center, center_off);
+    bool has_center = draw->layout_end[PANGO_ALIGN_LEFT] && draw->layout_end[PANGO_ALIGN_LEFT]->next;
+    bool has_right = draw->layout_end[PANGO_ALIGN_LEFT] && draw->layout_end[PANGO_ALIGN_CENTER]->next;
 
-    for (GList *it = layout_start[PANGO_ALIGN_CENTER]; it != NULL && it != layout_start[PANGO_ALIGN_RIGHT]; it = it->next) {
-        Layout *layout = it->data;
-        layout->x += center_off;
+    GList *center_start = has_center ? draw->layout_end[PANGO_ALIGN_LEFT]->next : NULL;
+    GList *right_start = has_right ? draw->layout_end[PANGO_ALIGN_CENTER]->next : NULL;
+
+    if (has_center) {
+        int center = round(draw->width / 2);
+        int center_off = center - draw->layout_width[PANGO_ALIGN_CENTER] / 2 - draw->layout_bx[PANGO_ALIGN_LEFT];
+
+        log_debug("Aligning center layout [center=%d, off=%d]", center, center_off);
+        layout_adjust(center_start, right_start, center_off);
     }
 
-    int right = width - layout_width[PANGO_ALIGN_RIGHT];
-    int right_off = right - MAX(layout_end[PANGO_ALIGN_LEFT], layout_end[PANGO_ALIGN_CENTER]);
-    log_debug("Aligning right layout [x=%d, off=%d]", right, right_off);
+    if (has_right) {
+        int right = draw->width - draw->layout_width[PANGO_ALIGN_RIGHT];
+        int right_off = right - MAX(draw->layout_bx[PANGO_ALIGN_LEFT], draw->layout_bx[PANGO_ALIGN_CENTER]);
 
-    for (GList *it = layout_start[PANGO_ALIGN_RIGHT]; it != NULL; it = it->next) {
-        Layout *layout = it->data;
-        layout->x += right_off;
+        log_debug("Aligning right layout [x=%d, off=%d]", right, right_off);
+        layout_adjust(right_start, NULL, right_off);
     }
 
     log_debug("Updated layouts");
@@ -343,6 +313,11 @@ void draw_set_background(Drawer *draw, Color background)
     draw->background = background;
 }
 
+void draw_set_separator(Drawer *draw, int sep)
+{
+    draw->sep = sep;
+}
+
 void draw_destroy(Drawer *draw)
 {
     g_list_free_full(draw->layouts, (GDestroyNotify)layout_destroy);
diff --git a/src/draw.h b/src/draw.h
index f68b4ab..0b1ac95 100644
--- a/src/draw.h
+++ b/src/draw.h
@@ -16,11 +16,17 @@ typedef struct {
 typedef struct {
     PangoFontDescription *desc;
     int height;
+    int width;
     int left_pad;
     int right_pad;
     int top_pad;
+    int sep;
     Color background;
     GList *layouts;
+    // Calculated by draw_compute_layout
+    GList *layout_end[3];
+    int layout_bx[3];
+    int layout_width[3];
 } Drawer;
 
 typedef struct {
@@ -42,6 +48,8 @@ void draw_paint(Drawer *draw, Window *win);
 
 void draw_set_background(Drawer *draw, Color background);
 
+void draw_set_separator(Drawer *draw, int sep);
+
 void draw_destroy(Drawer *draw);
 
 #endif