Bugfix [35841] WM_OT_context_[toggle/cycle/etc.] operators dont show shortcut

keys in menus (or tooltips) for properties they are used to toggle/cycle through

Some properties can be toggled using hotkeys via WM_OT_context_* operators, but
these hotkeys aren't really shown anywhere obvious like other hotkeys (i.e.
they're not shown in tooltips or menus). Although it is possible to look these
up in the userprefs/keymaps editor, it is quite tricky doing so, and most users
would just assume that since no shortcut is displayed, there simply isn't one at
all.

This commit introduces a slightly hacky fix which basically amounts to checking
if a property can be set by any of the few operators which are used for this
purpose. In order to keep this from being too sluggish, I've currently limited
this to only working on Editor (e.g. "Show Seconds" in Anim Editors) and
ToolSettings (e.g. "Use Proportional Edit") properties.

There are still some corner cases that would be nice to solve too (i.e. the
Pivot Type enum menu/dropdown should really be able to show the hotkeys which
have been assigned for each of those items, since they're by-and-large quite
hidden and obscure), though being able to show some of these is perhaps better
than not showing any!

3 files changed, 131 insertions, 2 deletions

diff --git a/source/blender/editors/include/UI_interface.h b/source/blender/editors/include/UI_interface.h
index b997d0ef6a0..b566fd360b6 100644
--- a/source/blender/editors/include/UI_interface.h
+++ b/source/blender/editors/include/UI_interface.h
@@ -534,7 +534,8 @@ enum {
 	BUT_GET_TIP,
 	BUT_GET_RNA_TIP,
 	BUT_GET_RNAENUM_TIP,
-	BUT_GET_OP_KEYMAP
+	BUT_GET_OP_KEYMAP,
+	BUT_GET_PROP_KEYMAP
 };
 
 typedef struct uiStringInfo {
diff --git a/source/blender/editors/interface/interface.c b/source/blender/editors/interface/interface.c
index 19eb978a01e..9ac499fc94b 100644
--- a/source/blender/editors/interface/interface.c
+++ b/source/blender/editors/interface/interface.c
@@ -901,6 +901,114 @@ static bool ui_but_event_operator_string(const bContext *C, uiBut *but, char *bu
 	return found;
 }
 
+static bool ui_but_event_property_operator_string(const bContext *C, uiBut *but, char *buf, const size_t buf_len)
+{	
+	/* context toggle operator names to check... */
+	const char *ctx_toggle_opnames[] = {
+		"WM_OT_context_toggle",
+		"WM_OT_context_toggle_enum",
+		"WM_OT_context_cycle_int",
+		"WM_OT_context_cycle_enum",
+		"WM_OT_context_cycle_array",
+		"WM_OT_context_menu_enum",
+		NULL
+	};		
+	const size_t num_ops = sizeof(ctx_toggle_opnames) / sizeof(const char *);
+	
+	bool found = false;
+	
+	/* this version is only for finding hotkeys for properties (which get set via context using operators) */
+	if (but->rnaprop) {
+		/* to avoid massive slowdowns on property panels, for now, we only check the 
+		 * hotkeys for Editor / Scene settings...
+		 *
+		 * TODO: userpref settings?
+		 */
+		// TODO: value (for enum stuff)?
+		char *data_path = NULL;
+		
+		if (but->rnapoin.id.data) {
+			ID *id = but->rnapoin.id.data;
+			
+			if (GS(id->name) == ID_SCR) {
+				/* screen/editor property 
+				 * NOTE: in most cases, there is actually no info for backwards tracing 
+				 * how to get back to ID from the editor data we may be dealing with
+				 */
+				if (RNA_struct_is_a(but->rnapoin.type, &RNA_Space)) {
+					/* data should be directly on here... */
+					data_path = BLI_sprintfN("space_data.%s", RNA_property_identifier(but->rnaprop));
+				}
+				else {
+					/* special exceptions for common nested data in editors... */
+					if (RNA_struct_is_a(but->rnapoin.type, &RNA_DopeSheet)) {
+						/* dopesheet filtering options... */
+						data_path = BLI_sprintfN("space_data.dopesheet.%s", RNA_property_identifier(but->rnaprop));
+					}
+				}
+			}
+			else if (GS(id->name) == ID_SCE) {
+				if (RNA_struct_is_a(but->rnapoin.type, &RNA_ToolSettings)) {
+					/* toolsettings property 
+					 * NOTE: toolsettings is usually accessed directly (i.e. not through scene)
+					 */
+					data_path = RNA_path_from_ID_to_property(&but->rnapoin, but->rnaprop);
+				}
+				else {
+					/* scene property */
+					char *path = RNA_path_from_ID_to_property(&but->rnapoin, but->rnaprop);
+					
+					if (path) {
+						data_path = BLI_sprintfN("scene.%s", path);
+						MEM_freeN(path);
+					}
+					else {
+						printf("ERROR in %s(): Couldn't get path for scene property - %s\n", 
+						       __func__, RNA_property_identifier(but->rnaprop));
+					}
+				}
+			}
+			else {
+				//puts("other id");
+			}
+			
+			//printf("prop shortcut: '%s' (%s)\n", RNA_property_identifier(but->rnaprop), data_path);
+		}
+		
+		/* we have a datapath! */
+		if (data_path) {
+			size_t i;
+			
+			/* create a property to host the "datapath" property we're sending to the operators */
+			IDProperty *prop_path;
+			IDProperty *prop_path_value;
+			
+			IDPropertyTemplate val = {0};
+			prop_path = IDP_New(IDP_GROUP, &val, __func__);
+			prop_path_value = IDP_NewString(data_path, "data_path", strlen(data_path) + 1); /* len + 1, or else will be truncated */
+			IDP_AddToGroup(prop_path, prop_path_value);
+			
+			/* check each until one works... */
+			for (i = 0; (i < num_ops) && (ctx_toggle_opnames[i]); i++) {
+				//printf("\t%s\n", ctx_toggle_opnames[i]);
+				if (WM_key_event_operator_string(C, ctx_toggle_opnames[i], WM_OP_INVOKE_REGION_WIN, prop_path, false,
+				                                 buf, buf_len))
+				{
+					found = true;
+					break;
+				}
+			}
+			
+			/* cleanup */
+			IDP_FreeProperty(prop_path);
+			MEM_freeN(prop_path);
+			MEM_freeN(data_path);
+		}
+	}
+	
+	return found;
+}
+
 static void ui_menu_block_set_keymaps(const bContext *C, uiBlock *block)
 {
 	uiBut *but;
@@ -915,6 +1023,9 @@ static void ui_menu_block_set_keymaps(const bContext *C, uiBlock *block)
 		if (ui_but_event_operator_string(C, but, buf, sizeof(buf))) {
 			ui_but_add_shortcut(but, buf, FALSE);
 		}
+		else if (ui_but_event_property_operator_string(C, but, buf, sizeof(buf))) {
+			ui_but_add_shortcut(but, buf, FALSE);
+		}
 	}
 }
 
@@ -4011,6 +4122,13 @@ void uiButGetStrInfo(bContext *C, uiBut *but, ...)
 				}
 			}
 		}
+		else if (type == BUT_GET_PROP_KEYMAP) {
+			/* for properties that are bound to one of the context cycle, etc. keys... */
+			char buf[128];
+			if (ui_but_event_property_operator_string(C, but, buf, sizeof(buf))) {
+				tmp = BLI_strdup(buf);
+			}
+		}
 
 		si->strinfo = tmp;
 	}
diff --git a/source/blender/editors/interface/interface_regions.c b/source/blender/editors/interface/interface_regions.c
index fbe23b1a1ed..9558baf0334 100644
--- a/source/blender/editors/interface/interface_regions.c
+++ b/source/blender/editors/interface/interface_regions.c
@@ -439,6 +439,7 @@ ARegion *ui_tooltip_create(bContext *C, ARegion *butregion, uiBut *but)
 	uiStringInfo enum_label = {BUT_GET_RNAENUM_LABEL, NULL};
 	uiStringInfo enum_tip = {BUT_GET_RNAENUM_TIP, NULL};
 	uiStringInfo op_keymap = {BUT_GET_OP_KEYMAP, NULL};
+	uiStringInfo prop_keymap = {BUT_GET_PROP_KEYMAP, NULL};
 	uiStringInfo rna_struct = {BUT_GET_RNASTRUCT_IDENTIFIER, NULL};
 	uiStringInfo rna_prop = {BUT_GET_RNAPROP_IDENTIFIER, NULL};
 
@@ -448,7 +449,7 @@ ARegion *ui_tooltip_create(bContext *C, ARegion *butregion, uiBut *but)
 	/* create tooltip data */
 	data = MEM_callocN(sizeof(uiTooltipData), "uiTooltipData");
 
-	uiButGetStrInfo(C, but, &but_tip, &enum_label, &enum_tip, &op_keymap, &rna_struct, &rna_prop, NULL);
+	uiButGetStrInfo(C, but, &but_tip, &enum_label, &enum_tip, &op_keymap, &prop_keymap, &rna_struct, &rna_prop, NULL);
 
 	/* special case, enum rna buttons only have enum item description,
 	 * use general enum description too before the specific one */
@@ -480,6 +481,13 @@ ARegion *ui_tooltip_create(bContext *C, ARegion *butregion, uiBut *but)
 		data->color_id[data->totline] = UI_TIP_LC_NORMAL;
 		data->totline++;
 	}
+	
+	/* Property context-toggle shortcut */
+	if (prop_keymap.strinfo) {
+		BLI_snprintf(data->lines[data->totline], sizeof(data->lines[0]), TIP_("Shortcut: %s"), prop_keymap.strinfo);
+		data->color_id[data->totline] = UI_TIP_LC_NORMAL;
+		data->totline++;
+	}
 
 	if (ELEM3(but->type, TEX, SEARCH_MENU, SEARCH_MENU_UNLINK)) {
 		/* full string */
@@ -614,6 +622,8 @@ ARegion *ui_tooltip_create(bContext *C, ARegion *butregion, uiBut *but)
 		MEM_freeN(enum_tip.strinfo);
 	if (op_keymap.strinfo)
 		MEM_freeN(op_keymap.strinfo);
+	if (prop_keymap.strinfo)
+		MEM_freeN(prop_keymap.strinfo);
 	if (rna_struct.strinfo)
 		MEM_freeN(rna_struct.strinfo);
 	if (rna_prop.strinfo)