UI: Add initial "grid view"

Part of T98560.
See https://wiki.blender.org/wiki/Source/Interface/Views

Adds all the basic functionality needed for grid views. They display
items in a grid of rows and columns, typically with a preview image and
a label underneath. Think of the main region in the Asset Browser.

Current features:
- Active item
- Notifier listening (also added this to the tree view)
- Performance: Skip adding buttons that are not scrolled into view
  (solves performance problems for big asset libraries, for example).
- Custom item size
- Preview items (items that draw a preview with a label underneath)
- Margins between items scale so the entire region width is filled with
  column, rather than leaving a big empty block at the right if there's
  not enough space for another column (like the File and current Asset
Browser does it).
- "Data-View Item" theme colors. Not shown in the UI yet.

No user visible changes expected since the grid views aren't used for
anything yet.

This was developed as part of a rewrite of the Asset Browser UI
(`asset-browser-grid-view` branch), see T95653. There's no reason to
keep this part in a branch, continuing development in master makes
things easier.

Grid and tree views have a lot of very similar code, so I'm planning to
unify them to a degree. I kept things separate for the start to first
find out how much and what exactly makes sense to override.

1 files changed, 29 insertions, 0 deletions

diff --git a/source/blender/editors/include/UI_interface.h b/source/blender/editors/include/UI_interface.h
index 22f5ecb35b8..b2ec2102ddd 100644
--- a/source/blender/editors/include/UI_interface.h
+++ b/source/blender/editors/include/UI_interface.h
@@ -64,6 +64,7 @@ struct wmKeyMapItem;
 struct wmMsgBus;
 struct wmOperator;
 struct wmOperatorType;
+struct wmRegionListenerParams;
 struct wmWindow;
 
 typedef struct uiBlock uiBlock;
@@ -75,6 +76,10 @@ typedef struct uiPopupBlockHandle uiPopupBlockHandle;
 typedef struct uiTreeViewHandle uiTreeViewHandle;
 /* C handle for C++ #ui::AbstractTreeViewItem type. */
 typedef struct uiTreeViewItemHandle uiTreeViewItemHandle;
+/* C handle for C++ #ui::AbstractGridView type. */
+typedef struct uiGridViewHandle uiGridViewHandle;
+/* C handle for C++ #ui::AbstractGridViewItem type. */
+typedef struct uiGridViewItemHandle uiGridViewItemHandle;
 
 /* Defines */
 
@@ -390,6 +395,8 @@ typedef enum {
   UI_BTYPE_DECORATOR = 58 << 9,
   /* An item in a tree view. Parent items may be collapsible. */
   UI_BTYPE_TREEROW = 59 << 9,
+  /* An item in a grid view. */
+  UI_BTYPE_GRID_TILE = 60 << 9,
 } eButType;
 
 #define BUTTYPE (63 << 9)
@@ -1740,6 +1747,14 @@ struct PointerRNA *UI_but_extra_operator_icon_add(uiBut *but,
 struct wmOperatorType *UI_but_extra_operator_icon_optype_get(struct uiButExtraOpIcon *extra_icon);
 struct PointerRNA *UI_but_extra_operator_icon_opptr_get(struct uiButExtraOpIcon *extra_icon);
 
+/**
+ * A decent size for a button (typically #UI_BTYPE_PREVIEW_TILE) to display a nicely readable
+ * preview with label in.
+ */
+int UI_preview_tile_size_x(void);
+int UI_preview_tile_size_y(void);
+int UI_preview_tile_size_y_no_label(void);
+
 /* Autocomplete
  *
  * Tab complete helper functions, for use in uiButCompleteFunc callbacks.
@@ -3185,7 +3200,12 @@ void UI_interface_tag_script_reload(void);
 /* Support click-drag motion which presses the button and closes a popover (like a menu). */
 #define USE_UI_POPOVER_ONCE
 
+void UI_block_views_listen(const uiBlock *block,
+                           const struct wmRegionListenerParams *listener_params);
+
+bool UI_grid_view_item_is_active(const uiGridViewItemHandle *item_handle);
 bool UI_tree_view_item_is_active(const uiTreeViewItemHandle *item);
+bool UI_grid_view_item_matches(const uiGridViewItemHandle *a, const uiGridViewItemHandle *b);
 bool UI_tree_view_item_matches(const uiTreeViewItemHandle *a, const uiTreeViewItemHandle *b);
 /**
  * Attempt to start dragging the tree-item \a item_. This will not work if the tree item doesn't
@@ -3223,6 +3243,15 @@ uiTreeViewItemHandle *UI_block_tree_view_find_item_at(const struct ARegion *regi
                                                       const int xy[2]) ATTR_NONNULL(1, 2);
 uiTreeViewItemHandle *UI_block_tree_view_find_active_item(const struct ARegion *region);
 
+/**
+ * Listen to \a notifier, returning true if the region should redraw.
+ */
+bool UI_tree_view_listen_should_redraw(const uiTreeViewHandle *view, const wmNotifier *notifier);
+/**
+ * Listen to \a notifier, returning true if the region should redraw.
+ */
+bool UI_grid_view_listen_should_redraw(const uiGridViewHandle *view, const wmNotifier *notifier);
+
 #ifdef __cplusplus
 }
 #endif