Make scrollbar autohideable

5 files changed, 43 insertions, 24 deletions

diff --git a/lib/bemenu.h b/lib/bemenu.h
index b5598d0..4010683 100644
--- a/lib/bemenu.h
+++ b/lib/bemenu.h
@@ -135,6 +135,23 @@ enum bm_filter_mode {
 };
 
 /**
+ * Scrollbar display mode constants for bm_menu instance scrollbar.
+ *
+ * - @link ::bm_run_result BM_SCROLLBAR_ALWAYS @endlink means that scrollbar is not displayed.
+ * - @link ::bm_run_result BM_SCROLLBAR_ALWAYS @endlink means that scrollbar is displayed always.
+ * - @link ::bm_run_result BM_SCROLLBAR_AUTOHIDE @endlink means that scrollbar is only displayed when there are more items than lines.
+ *
+ * @link ::bm_scrollbar_mode BM_SCROLLBAR_LAST @endlink is provided for enumerating scrollbar modes.
+ * Using it as scrollbar mode however provides exactly same functionality as BM_SCROLLBAR_NONE.
+ */
+enum bm_scrollbar_mode {
+    BM_SCROLLBAR_NONE,
+    BM_SCROLLBAR_ALWAYS,
+    BM_SCROLLBAR_AUTOHIDE,
+    BM_SCROLLBAR_LAST,
+};
+
+/**
  * Result constants from bm_menu_run_with_key function.
  *
  * - @link ::bm_run_result BM_RUN_RESULT_RUNNING @endlink means that menu is running and thus should be still renderer && ran.
@@ -389,20 +406,20 @@ bool bm_menu_set_color(struct bm_menu *menu, enum bm_color color, const char *he
 const char* bm_menu_get_color(const struct bm_menu *menu, enum bm_color color);
 
 /**
- * Display scrollbar at left side of the menu.
+ * Set scrollbar display mode.
  *
  * @param menu bm_menu instance to set scrollbar for.
- * @param scrollbar true for scrollbar, false for no scrollbar.
+ * @param mode bm_scrollbar_mode constant.
  */
-void bm_menu_set_scrollbar(struct bm_menu *menu, bool scrollbar);
+void bm_menu_set_scrollbar(struct bm_menu *menu, enum bm_scrollbar_mode mode);
 
 /**
- * Is scrollbar being displayed on the menu?
+ * Return current scrollbar display mode.
  *
  * @param menu bm_menu instance where to get scrollbar display state from.
- * @return true if scrollbar displayed, false otherwise.
+ * @return bm_scrollbar_mode constant.
  */
-bool bm_menu_get_scrollbar(struct bm_menu *menu);
+enum bm_scrollbar_mode bm_menu_get_scrollbar(struct bm_menu *menu);
 
 /**
  * Display menu at bottom of the screen.
diff --git a/lib/internal.h b/lib/internal.h
index 5291b56..52d4125 100644
--- a/lib/internal.h
+++ b/lib/internal.h
@@ -274,6 +274,11 @@ struct bm_menu {
     enum bm_filter_mode filter_mode;
 
     /**
+     * Current Scrollbar display mode.
+     */
+    enum bm_scrollbar_mode scrollbar;
+
+    /**
      * Should selection be wrapped?
      */
     bool wrap;
@@ -287,11 +292,6 @@ struct bm_menu {
      * Is menu grabbed?
      */
     bool grabbed;
-
-    /**
-     * Scrollbar enabled?
-     */
-    bool scrollbar;
 };
 
 /* library.c */
diff --git a/lib/menu.c b/lib/menu.c
index b816b28..2eea897 100644
--- a/lib/menu.c
+++ b/lib/menu.c
@@ -298,12 +298,12 @@ char* bm_menu_get_color(const struct bm_menu *menu, enum bm_color color)
 }
 
 void
-bm_menu_set_scrollbar(struct bm_menu *menu, bool scrollbar)
+bm_menu_set_scrollbar(struct bm_menu *menu, enum bm_scrollbar_mode mode)
 {
-    menu->scrollbar = scrollbar;
+    menu->scrollbar = (mode == BM_SCROLLBAR_LAST ? BM_SCROLLBAR_NONE : mode);
 }
 
-bool
+enum bm_scrollbar_mode
 bm_menu_get_scrollbar(struct bm_menu *menu)
 {
     return menu->scrollbar;
diff --git a/lib/renderers/cairo.h b/lib/renderers/cairo.h
index 1a4f7c2..59f61d3 100644
--- a/lib/renderers/cairo.h
+++ b/lib/renderers/cairo.h
@@ -197,17 +197,18 @@ bm_cairo_paint(struct cairo *cairo, uint32_t width, uint32_t height, uint32_t ma
     paint.pos = (struct pos){ (menu->title ? 2 : 0) + result.x_advance, 2 };
     paint.box = (struct box){ (menu->title ? 2 : 4), 0, 2, 2, width - paint.pos.x, 0 };
     bm_cairo_draw_line(cairo, &paint, &result, "%s", (menu->filter ? menu->filter : ""));
+    const uint32_t titleh = result.height;
+    out_result->height = titleh;
 
     uint32_t count;
     struct bm_item **items = bm_menu_get_filtered_items(menu, &count);
     uint32_t lines = (menu->lines > 0 ? menu->lines : 1);
-    uint32_t titleh = result.height;
-    out_result->height = titleh;
 
     if (lines > 1) {
         /* vertical mode */
 
-        uint32_t spacing_x = (menu->scrollbar ? 4 : 0);
+        const bool scrollbar = (menu->scrollbar > BM_SCROLLBAR_NONE && (menu->scrollbar != BM_SCROLLBAR_AUTOHIDE || count > lines) ? true : false);
+        const uint32_t spacing_x = (scrollbar ? 4 : 0);
         uint32_t spacing_y = 0; // 0 == variable width spacing
         if (lines > max_height / titleh) {
             /* there is more lines than screen can fit, enter fixed spacing mode */
@@ -251,17 +252,17 @@ bm_cairo_paint(struct cairo *cairo, uint32_t width, uint32_t height, uint32_t ma
             out_result->displayed++;
         }
 
-        if (menu->scrollbar && count > 0) {
+        if (scrollbar && count > 0) {
             bm_cairo_color_from_menu_color(menu, BM_COLOR_SCROLLBAR_BG, &paint.bg);
             bm_cairo_color_from_menu_color(menu, BM_COLOR_SCROLLBAR_FG, &paint.fg);
 
-            uint32_t sheight = out_result->height - titleh;
+            const uint32_t sheight = out_result->height - titleh;
             cairo_set_source_rgba(cairo->cr, paint.bg.r, paint.bg.b, paint.bg.g, paint.bg.a);
             cairo_rectangle(cairo->cr, 0, titleh, 2, sheight);
             cairo_fill(cairo->cr);
 
-            uint32_t size = sheight / lines;
-            uint32_t percent = (menu->index / (float)(count - 1)) * (sheight - size);
+            const uint32_t size = sheight / lines;
+            const uint32_t percent = (menu->index / (float)(count - 1)) * (sheight - size);
             cairo_set_source_rgba(cairo->cr, paint.fg.r, paint.fg.b, paint.fg.g, paint.fg.a);
             cairo_rectangle(cairo->cr, 0, titleh + percent, 2, size);
             cairo_fill(cairo->cr);
diff --git a/lib/renderers/curses/curses.c b/lib/renderers/curses/curses.c
index 852eb88..1f81775 100644
--- a/lib/renderers/curses/curses.c
+++ b/lib/renderers/curses/curses.c
@@ -186,11 +186,12 @@ render(const struct bm_menu *menu)
 
     uint32_t count, cl = 1;
     const uint32_t lines = getmaxy(curses.stdscr);
-    const int32_t prefix_x = (menu->prefix ? bm_utf8_string_screen_width(menu->prefix) : 0);
-    const int32_t offset_x = (menu->scrollbar ? 2 : 0);
     if (lines > 1) {
         uint32_t displayed = 0;
         struct bm_item **items = bm_menu_get_filtered_items(menu, &count);
+        const bool scrollbar = (menu->scrollbar > BM_SCROLLBAR_NONE && (menu->scrollbar != BM_SCROLLBAR_AUTOHIDE || count > lines) ? true : false);
+        const int32_t offset_x = (scrollbar ? 2 : 0);
+        const int32_t prefix_x = (menu->prefix ? bm_utf8_string_screen_width(menu->prefix) : 0);
         for (uint32_t i = (menu->index / (lines - 1)) * (lines - 1); i < count && cl < lines; ++i) {
             bool highlighted = (items[i] == bm_menu_get_highlighted_item(menu));
             int32_t color = (highlighted ? 2 : (bm_menu_item_is_selected(menu, items[i]) ? 1 : 0));
@@ -204,7 +205,7 @@ render(const struct bm_menu *menu)
             ++displayed;
         }
 
-        if (menu->scrollbar) {
+        if (scrollbar) {
             attron(COLOR_PAIR(1));
             uint32_t percent = (menu->index / (float)(count - 1)) * (displayed - 1);
             mvprintw(1 + percent, 0, "▒");