Outliner: Tooltips for reorder operators

I really would prefer if we were to use the dropbox API for this.
That said, we now have some tooltips that work.

I'm using the new draw callback draw API for outliner tooltips.

Reviewers: mont29

Subscribers: venomgfx, mano-wii, Severin

Differential Revision: https://developer.blender.org/D3020

2 files changed, 106 insertions, 7 deletions

diff --git a/source/blender/editors/space_outliner/outliner_intern.h b/source/blender/editors/space_outliner/outliner_intern.h
index 1be709415e8..b06c9b85eb8 100644
--- a/source/blender/editors/space_outliner/outliner_intern.h
+++ b/source/blender/editors/space_outliner/outliner_intern.h
@@ -107,6 +107,7 @@ typedef struct TreeElement {
 		TreeElementInsertType insert_type;
 		/* the element before/after/into which we may insert the dragged one (NULL to insert at top) */
 		struct TreeElement *insert_handle;
+		void *tooltip_draw_handle;
 	} *drag_data;
 } TreeElement;
 
diff --git a/source/blender/editors/space_outliner/outliner_ops.c b/source/blender/editors/space_outliner/outliner_ops.c
index 5f73f176e2e..599096c0ee9 100644
--- a/source/blender/editors/space_outliner/outliner_ops.c
+++ b/source/blender/editors/space_outliner/outliner_ops.c
@@ -33,9 +33,13 @@
 #include "BLI_listbase.h"
 #include "BLI_math.h"
 
+#include "BLT_translation.h"
+
 #include "BKE_context.h"
 #include "BKE_main.h"
 
+#include "GPU_immediate.h"
+
 #include "RNA_access.h"
 
 #include "UI_interface.h"
@@ -48,6 +52,11 @@
 
 #include "outliner_intern.h"
 
+typedef struct OutlinerDragDropTooltip {
+	TreeElement *te;
+	void *handle;
+} OutlinerDragDropTooltip;
+
 enum {
 	OUTLINER_ITEM_DRAG_CANCEL,
 	OUTLINER_ITEM_DRAG_CONFIRM,
@@ -69,9 +78,15 @@ static TreeElement *outliner_item_drag_element_find(SpaceOops *soops, ARegion *a
 	return outliner_find_item_at_y(soops, &soops->tree, my);
 }
 
-static void outliner_item_drag_end(TreeElement *dragged_te)
+static void outliner_item_drag_end(wmWindow *win, OutlinerDragDropTooltip *data)
 {
-	MEM_SAFE_FREE(dragged_te->drag_data);
+	MEM_SAFE_FREE(data->te->drag_data);
+
+	if (data->handle) {
+		WM_draw_cb_exit(win, data->handle);
+	}
+
+	MEM_SAFE_FREE(data);
 }
 
 static void outliner_item_drag_get_insert_data(
@@ -164,8 +179,13 @@ static void outliner_item_drag_handle(
 	te_dragged->drag_data->insert_handle = te_insert_handle;
 }
 
-static bool outliner_item_drag_drop_apply(Main *bmain, SpaceOops *soops, TreeElement *dragged_te, const wmEvent *event)
+static bool outliner_item_drag_drop_apply(
+        Main *bmain,
+        SpaceOops *soops,
+        OutlinerDragDropTooltip *data,
+        const wmEvent *event)
 {
+	TreeElement *dragged_te = data->te;
 	TreeElement *insert_handle = dragged_te->drag_data->insert_handle;
 	TreeElementInsertType insert_type = dragged_te->drag_data->insert_type;
 
@@ -190,7 +210,8 @@ static int outliner_item_drag_drop_modal(bContext *C, wmOperator *op, const wmEv
 	Main *bmain = CTX_data_main(C);
 	ARegion *ar = CTX_wm_region(C);
 	SpaceOops *soops = CTX_wm_space_outliner(C);
-	TreeElement *te_dragged = op->customdata;
+	OutlinerDragDropTooltip *data = op->customdata;
+	TreeElement *te_dragged = data->te;
 	int retval = OPERATOR_RUNNING_MODAL;
 	bool redraw = false;
 	bool skip_rebuild = true;
@@ -198,7 +219,7 @@ static int outliner_item_drag_drop_modal(bContext *C, wmOperator *op, const wmEv
 	switch (event->type) {
 		case EVT_MODAL_MAP:
 			if (event->val == OUTLINER_ITEM_DRAG_CONFIRM) {
-				if (outliner_item_drag_drop_apply(bmain, soops, te_dragged, event)) {
+				if (outliner_item_drag_drop_apply(bmain, soops, data, event)) {
 					skip_rebuild = false;
 				}
 				retval = OPERATOR_FINISHED;
@@ -210,7 +231,7 @@ static int outliner_item_drag_drop_modal(bContext *C, wmOperator *op, const wmEv
 				BLI_assert(0);
 			}
 			WM_event_add_mousemove(C); /* update highlight */
-			outliner_item_drag_end(te_dragged);
+			outliner_item_drag_end(CTX_wm_window(C), data);
 			redraw = true;
 			break;
 		case MOUSEMOVE:
@@ -229,6 +250,78 @@ static int outliner_item_drag_drop_modal(bContext *C, wmOperator *op, const wmEv
 	return retval;
 }
 
+static const char *outliner_drag_drop_tooltip_get(
+        const TreeElement *te_float)
+{
+	const char *name = NULL;
+	TreeStoreElem *tselem = TREESTORE(te_float);
+
+	const TreeElement *te_insert = te_float->drag_data->insert_handle;
+	if (ELEM(tselem->type, TSE_LAYER_COLLECTION, TSE_SCENE_COLLECTION)) {
+		if (te_insert == NULL) {
+			name = TIP_("Move collection");
+		}
+		else {
+			switch (te_float->drag_data->insert_type) {
+				case TE_INSERT_BEFORE:
+					if (te_insert->prev) {
+						name = TIP_("Move between collections");
+					}
+					else {
+						name = TIP_("Move before collection");
+					}
+					break;
+				case TE_INSERT_AFTER:
+					if (te_insert->next) {
+						name = TIP_("Move between collections");
+					}
+					else {
+						name = TIP_("Move after collection");
+					}
+					break;
+				case TE_INSERT_INTO:
+					name = TIP_("Move inside collection");
+					break;
+			}
+		}
+	}
+	else if ((tselem->type == 0) && (te_float->idcode == ID_OB)) {
+		name = TIP_("Move to collection (Ctrl to add)");
+	}
+
+	return name;
+}
+
+static void outliner_drag_drop_tooltip_cb(const wmWindow *win, void *vdata)
+{
+	OutlinerDragDropTooltip *data = vdata;
+	const char *tooltip;
+
+	int cursorx, cursory;
+	int x, y;
+
+	tooltip = outliner_drag_drop_tooltip_get(data->te);
+	if (tooltip == NULL) {
+		return;
+	}
+
+	cursorx = win->eventstate->x;
+	cursory = win->eventstate->y;
+
+	x = cursorx + U.widget_unit;
+	y = cursory - U.widget_unit;
+
+	/* Drawing. */
+	const uiFontStyle *fstyle = UI_FSTYLE_WIDGET;
+
+	const float col_fg[4] = {1.0f, 1.0f, 1.0f, 1.0f};
+	const float col_bg[4] = {0.0f, 0.0f, 0.0f, 0.2f};
+
+	glEnable(GL_BLEND);
+	UI_fontstyle_draw_simple_backdrop(fstyle, x, y, tooltip, col_fg, col_bg);
+	glDisable(GL_BLEND);
+}
+
 static int outliner_item_drag_drop_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
 	ARegion *ar = CTX_wm_region(C);
@@ -239,7 +332,10 @@ static int outliner_item_drag_drop_invoke(bContext *C, wmOperator *op, const wmE
 		return (OPERATOR_FINISHED | OPERATOR_PASS_THROUGH);
 	}
 
-	op->customdata = te_dragged;
+	OutlinerDragDropTooltip *data = MEM_mallocN(sizeof(OutlinerDragDropTooltip), __func__);
+	data->te = te_dragged;
+
+	op->customdata = data;
 	te_dragged->drag_data = MEM_callocN(sizeof(*te_dragged->drag_data), __func__);
 	/* by default we don't change the item position */
 	te_dragged->drag_data->insert_handle = te_dragged;
@@ -251,6 +347,8 @@ static int outliner_item_drag_drop_invoke(bContext *C, wmOperator *op, const wmE
 
 	WM_event_add_modal_handler(C, op);
 
+	data->handle = WM_draw_cb_activate(CTX_wm_window(C), outliner_drag_drop_tooltip_cb, data);
+
 	return OPERATOR_RUNNING_MODAL;
 }