Add button alignment and layouting

5 files changed, 113 insertions, 21 deletions

diff --git a/src/button.c b/src/button.c
index 3a4e311..11ca2b7 100644
--- a/src/button.c
+++ b/src/button.c
@@ -2,10 +2,11 @@
 
 #include "button.h"
 
-Button *button_create(const char *text)
+Button *button_create(const char *text, PangoAlignment align)
 {
 	Button *btn = g_malloc0(sizeof(Button));
 	btn->text = g_strdup(text);
+	btn->align = align;
 	return btn;
 }
 
diff --git a/src/button.h b/src/button.h
index 7df70d3..1d736e6 100644
--- a/src/button.h
+++ b/src/button.h
@@ -2,6 +2,7 @@
 #define COMET_BUTTON_H
 
 #include <stdbool.h>
+#include <pango/pangocairo.h>
 
 // TODO: Generic button shapes/actions
 
@@ -12,9 +13,10 @@ typedef void (* ButtonAction)(Button *btn);
 struct Button {
     ButtonAction action;
     char *text;
+    PangoAlignment align;
 };
 
-Button *button_create(const char *text);
+Button *button_create(const char *text, PangoAlignment align);
 
 void button_set_action(Button *btn, ButtonAction action);
 
diff --git a/src/comet.c b/src/comet.c
index 268d846..a1bc605 100644
--- a/src/comet.c
+++ b/src/comet.c
@@ -69,16 +69,24 @@ int main(int argc, char **argv)
 
     for (int i = 0; i < 9; ++i) {
         char text[] = { '1' + i, '\0' };
-        Button *btn = button_create(text);
+        Button *btn = button_create(text, PANGO_ALIGN_LEFT);
         button_set_action(btn, action);
         state_add_button(state, btn);
     }
 
-    Button *btn = button_create("long button");
-    button_set_action(btn, action);
-    state_add_button(state, btn);
+    Button *long_btn = button_create("long button", PANGO_ALIGN_CENTER);
+    button_set_action(long_btn, action);
+    state_add_button(state, long_btn);
 
-    draw_compute_layout(draw, state->btns, window_get_context(win));
+    Button *date_btn = button_create("date = today", PANGO_ALIGN_RIGHT);
+    button_set_action(date_btn, action);
+    state_add_button(state, date_btn);
+
+    Button *u_btn = button_create("U", PANGO_ALIGN_RIGHT);
+    button_set_action(u_btn, action);
+    state_add_button(state, u_btn);
+
+    draw_compute_layout(draw, win, state->btns);
 
     connect_attach_state(con, state);
     connect_attach_source(con);
diff --git a/src/draw.c b/src/draw.c
index 91ae186..310bca9 100644
--- a/src/draw.c
+++ b/src/draw.c
@@ -41,18 +41,27 @@ Drawable *draw_create(const char *font, int height, int left_pad, int right_pad,
     return draw;
 }
 
-void draw_paint(Drawable *draw, Window *win)
+static void compute_width(Drawable *draw, Window *win, int *width, int *height)
 {
     // FIXME: Does not work for scale != 1
     //double scale = window_get_scale(win);
     double scale = 1;
 
-    int screen_width, screen_height;
-    window_get_screen_size(win, &screen_width, &screen_height);
+    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 * scale);
+    *height = round(draw->height * scale);
+}
+
+void draw_paint(Drawable *draw, Window *win)
+{
+    // FIXME: Does not work for scale != 1
+    //double scale = window_get_scale(win);
+    double scale = 1;
 
-    int width0  = screen_width - draw->right_pad - draw->left_pad;
-    int width  = round(width0 * scale);
-    int height = round(draw->height * scale);
+    int width, height;
+    compute_width(draw, win, &width, &height);
 
     cairo_surface_t *surface = cairo_image_surface_create(CAIRO_FORMAT_ARGB32, width, height);
 
@@ -112,13 +121,23 @@ void draw_paint(Drawable *draw, Window *win)
 
     // TODO: Move these somewhere else
     window_move(win, draw->left_pad, draw->top_pad);
-    window_resize(win, width0, draw->height);
+    window_resize(win, width, draw->height);
 
     window_paint_surface(win, surface, width, height);
     cairo_surface_destroy(surface);
 }
 
-void draw_compute_layout(Drawable *draw, GList *btns, cairo_t *cr)
+static gint align_compare(gconstpointer a, gconstpointer b)
+{
+    PangoAlignment a_align = ((Button *)a)->align;
+    PangoAlignment b_align = ((Button *)b)->align;
+
+    if (a_align < b_align) return -1;
+    if (a_align > b_align) return 1;
+    return 0;
+}
+
+void draw_compute_layout(Drawable *draw, Window *win, GList *btns)
 {
     g_list_free_full(draw->layouts, (GDestroyNotify)layout_destroy);
     draw->layouts = NULL;
@@ -127,20 +146,31 @@ void draw_compute_layout(Drawable *draw, GList *btns, cairo_t *cr)
     //double scale = window_get_scale(win);
     double scale = 1;
 
+    int width, height;
+    compute_width(draw, win, &width, &height);
+
     int x = 0;
-    int height = round(draw->height * scale);
     int radius = height / 2;
 
+    btns = g_list_sort(btns, align_compare);
+
+    GList *adjust_center = NULL;
+    GList *adjust_right = NULL;
+
+    int end_xs[3] = { 0 };
+    Button *prev = NULL;
+
     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);
+        layout->pl = pango_cairo_create_layout(window_get_context(win));
         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);
@@ -157,14 +187,65 @@ void draw_compute_layout(Drawable *draw, GList *btns, cairo_t *cr)
         layout->width = text_l == 1 ? height : layout->text_w + 2 * radius;
         layout->height = height;
 
-        draw->layouts = g_list_append(draw->layouts, layout);
+        draw->layouts = g_list_prepend(draw->layouts, layout);
+
+        if (prev != NULL) {
+            if (prev->align == btn->align) {
+                int sep = 10 * scale;
+                x += sep;
+                // Ugly update for layout
+                layout->x = x;
+            } else {
+                if (btn->align == PANGO_ALIGN_CENTER) adjust_center = draw->layouts;
+                else if (btn->align == PANGO_ALIGN_RIGHT) adjust_right = draw->layouts;
+            }
+        }
 
-        int sep = 10 * scale;
         int line_w = 1 * scale;
-        x += height + line_w * 2 + sep;
+        x += layout->width + line_w * 2;
+
+        prev = btn;
+        end_xs[btn->align] = x;
+    }
+
+    draw->layouts = g_list_reverse(draw->layouts);
+
+    int widths[3] = {
+        end_xs[0],
+        end_xs[1] - end_xs[0],
+        end_xs[2] - MAX(end_xs[1], end_xs[0]),
+    };
+
+    int start_xs[3] = {
+        0,
+        end_xs[0],
+        MAX(end_xs[1], end_xs[0]),
+    };
+
+    log_info("e1 = %d, e2 = %d, e3 = %d", end_xs[0], end_xs[1], end_xs[2]);
+    log_info("s1 = %d, s2 = %d, s3 = %d", start_xs[0], start_xs[1], start_xs[2]);
+    log_info("w1 = %d, w2 = %d, w3 = %d", widths[0], widths[1], widths[2]);
+
+    int center = round(width / 2);
+    int center_off = (center - widths[1] / 2) - start_xs[1];
+    log_debug("Aligning center layout [x=%d, off=%d]", center, center_off);
+
+    for (GList *it = adjust_center; it != adjust_right; it = it->next) {
+        Layout *layout = it->data;
+        layout->x += center_off;
+    }
+
+    int right = width - widths[2];
+    int right_off = right - start_xs[2];
+    log_debug("Aligning right layout [x=%d, off=%d]", right, right_off);
+
+    for (GList *it = adjust_right; it != NULL; it = it->next) {
+        Layout *layout = it->data;
+        layout->x += right_off;
     }
 
     log_debug("Updated layouts");
+    g_list_free(btns);
 }
 
 void draw_destroy(Drawable *draw)
diff --git a/src/draw.h b/src/draw.h
index 9c46900..3d3f7ed 100644
--- a/src/draw.h
+++ b/src/draw.h
@@ -30,7 +30,7 @@ typedef struct {
 
 Drawable *draw_create(const char *font, int height, int left_pad, int right_pad, int top_pad, double alpha);
 
-void draw_compute_layout(Drawable *draw, GList *btns, cairo_t *cr);
+void draw_compute_layout(Drawable *draw, Window *win, GList *btns);
 
 void draw_paint(Drawable *draw, Window *win);