Move layer actions into a context menu

So that we don't waste too much space for buttons that are not usually
needed.

src/goxel.h

@@ -395,6 +395,7 @@ enum {
     X(ICON_CLOUD,                   1, 4, 0),
     X(ICON_SHAPE,                   2, 4, 0),
     X(ICON_CLOSE,                   3, 4, 0),
+    X(ICON_THREE_DOTS,              4, 4, 0),
 
     X(ICON_TOOLS,                   0, 5, THEME_GROUP_ICON_EDIT),
     X(ICON_PALETTE,                 1, 5, THEME_GROUP_ICON_EDIT),

src/gui.cpp

@@ -169,6 +169,9 @@ typedef struct gui_t {
     int     is_row;
     float   item_size;
 
+    bool    is_context_menu;
+    int     context_menu_row;
+
     int     win_dir; // Store the current window direction (for scrolling).
 
     struct {
@@ -1324,7 +1327,12 @@ bool gui_button(const char *label, float size, int icon)
                             center + ImVec2(isize, isize),
                             uv0, uv1, get_icon_color(icon, 0));
     }
-    if (ret) on_click();
+    if (ret) {
+        on_click();
+        if (gui->is_context_menu)  {
+            ImGui::CloseCurrentPopup();
+        }
+    }
     if (gui->is_row) ImGui::SameLine();
     return ret;
 }
@@ -1857,3 +1865,28 @@ bool gui_want_capture_mouse(void)
     ImGuiIO& io = ImGui::GetIO();
     return io.WantCaptureMouse;
 }
+
+bool gui_context_menu_begin(const char *label)
+{
+    if (!ImGui::BeginPopupContextItem(label)) return false;
+    gui->is_context_menu = true;
+    gui->context_menu_row = gui->is_row;
+    gui->is_row = 0;
+    gui_group_begin(NULL);
+    return true;
+}
+
+void gui_context_menu_end(void)
+{
+    gui_group_end();
+    ImGui::EndPopup();
+    gui->is_context_menu = false;
+    gui->is_row = gui->context_menu_row;
+}
+
+void gui_context_menu_button(const char *label, int icon)
+{
+    if (gui_button(label, 0, icon)) {
+        ImGui::OpenPopup(label);
+    }
+}

src/gui.h

@@ -185,4 +185,11 @@ void gui_tooltip(const char *str);
 
 bool gui_view_cube(float x, float y, float w, float h);
 
+/*
+ * Support for context menu popup (like the one on layers).
+ */
+bool gui_context_menu_begin(const char *label);
+void gui_context_menu_end(void);
+void gui_context_menu_button(const char *label, int icon);
+
 #endif // GUI_H

src/gui/layers_panel.c

@@ -48,6 +48,39 @@ static const char *get_mode_name(int mode)
     }
 }
 
+static void layers_context_menu(void)
+{
+    layer_t *layer;
+    bool bounded;
+    char buf[256];
+
+    gui_action_button(ACTION_img_duplicate_layer, _(DUPLICATE), 1);
+    gui_action_button(ACTION_img_clone_layer, _(CLONE), 1);
+    gui_action_button(ACTION_img_merge_layer_down, _(MERGE_DOWN), 1);
+    gui_action_button(ACTION_img_merge_visible_layers, _(MERGE_VISIBLE), 1);
+
+    layer = goxel.image->active_layer;
+    bounded = !box_is_null(layer->box);
+
+    if (bounded && gui_button(_(CROP), 1, 0)) {
+        volume_crop(layer->volume, layer->box);
+    }
+    if (!box_is_null(goxel.image->box)) {
+        snprintf(buf, sizeof(buf), "%s: %s", _(CROP), _(IMAGE));
+        if (gui_button(buf, 1, 0))
+            volume_crop(layer->volume, goxel.image->box);
+    }
+    if (layer->shape) {
+        snprintf(buf, sizeof(buf), "▶ %s", _(VOLUME));
+        gui_action_button(ACTION_img_unclone_layer, buf, 1);
+    }
+
+    snprintf(buf, sizeof(buf), "%s: %s", _(ADD), _(SHAPE));
+    if (gui_action_button(ACTION_img_new_shape_layer, buf, 1)) {
+        action_exec2(ACTION_tool_set_move);
+    }
+}
+
 void gui_layers_panel(void)
 {
     layer_t *layer;
@@ -87,35 +120,17 @@ void gui_layers_panel(void)
     gui_action_button(ACTION_img_del_layer, NULL, 0);
     gui_action_button(ACTION_img_move_layer_up, NULL, 0);
     gui_action_button(ACTION_img_move_layer_down, NULL, 0);
-    gui_row_end();
-
-    gui_group_begin(NULL);
-    gui_action_button(ACTION_img_duplicate_layer, _(DUPLICATE), 1);
-    gui_action_button(ACTION_img_clone_layer, _(CLONE), 1);
-    gui_action_button(ACTION_img_merge_layer_down, _(MERGE_DOWN), 1);
-    gui_action_button(ACTION_img_merge_visible_layers, _(MERGE_VISIBLE), 1);
 
-    layer = goxel.image->active_layer;
-    bounded = !box_is_null(layer->box);
-    if (bounded && gui_button(_(CROP), 1, 0)) {
-        volume_crop(layer->volume, layer->box);
-    }
-    if (!box_is_null(goxel.image->box)) {
-        snprintf(buf, sizeof(buf), "%s: %s", _(CROP), _(IMAGE));
-        if (gui_button(buf, 1, 0))
-            volume_crop(layer->volume, goxel.image->box);
-    }
-    if (layer->shape) {
-        snprintf(buf, sizeof(buf), "▶ %s", _(VOLUME));
-        gui_action_button(ACTION_img_unclone_layer, buf, 1);
+    if (gui_context_menu_begin("##Actions")) {
+        layers_context_menu();
+        gui_context_menu_end();
     }
+    gui_context_menu_button("##Actions", ICON_THREE_DOTS);
 
-    snprintf(buf, sizeof(buf), "%s: %s", _(ADD), _(SHAPE));
-    if (gui_action_button(ACTION_img_new_shape_layer, buf, 1)) {
-        action_exec2(ACTION_tool_set_move);
-    }
+    gui_row_end();
 
-    gui_group_end();
+    layer = goxel.image->active_layer;
+    bounded = !box_is_null(layer->box);
 
     if (layer->base_id) {
         gui_group_begin(NULL);