2.5

Nice goodie: Preview renders!

- Added new preview.blend, allowing super wide cinemascope previews
- Draws nicely blended inside widget type, rounded corners
- Preview now renders using all available cpus/cores.
- Uses - hopefully rock stable - method, which doesn't copy or 
  allocate anything for previews, but just uses render API calls.
- Multiple previews are possible! But, added provision in Jobs
  manager to only render one preview job at a time. If you start
  more preview jobs, they're suspended until it's their turn.

Bugfix: new buttons context code crashed when going full-window.

Tweaks are still needed for notifiers. I have to figure out still
how to retrieve SpaceButs button view types...

source/blender/editors/interface/interface.c

@@ -662,12 +662,16 @@ void uiDrawBlock(const bContext *C, uiBlock *block)
 	else if(block->panel)
 		ui_draw_aligned_panel(ar, &style, block, &rect);
 
-	if(block->drawextra) block->drawextra(C, block);
-
 	/* widgets */
 	for(but= block->buttons.first; but; but= but->next) {
 		ui_but_to_pixelrect(&rect, ar, block, but);
 		ui_draw_but(ar, &style, but, &rect);
+		
+		/* temp? roundbox defines size/location of preview, and ID type */
+		if(but->type==ROUNDBOX)
+			if(block->drawextra) 
+				block->drawextra(C, but->poin, &rect);
+		
 	}
 	
 	/* restore matrix */
@@ -2968,7 +2972,7 @@ void uiBlockSetRenameFunc(uiBlock *block, uiButHandleRenameFunc func, void *arg1
 	
 }
 
-void uiBlockSetDrawExtraFunc(uiBlock *block, void (*func)())
+void uiBlockSetDrawExtraFunc(uiBlock *block, void (*func)(const bContext *C, void *idv, rcti *rect))
 {
 	block->drawextra= func;
 }

source/blender/editors/interface/interface_intern.h

@@ -255,7 +255,7 @@ struct uiBlock {
 	void *handle_func_arg;
 	
 	/* extra draw function for custom blocks */
-	void (*drawextra)();
+	void (*drawextra)(const struct bContext *C, void *idv, rcti *rect);
 
 	int afterval, flag;
 	

source/blender/editors/interface/interface_templates.c

@@ -33,6 +33,7 @@
 #include "BKE_utildefines.h"
 
 #include "ED_screen.h"
+#include "ED_previewrender.h"
 
 #include "RNA_access.h"
 
@@ -1277,6 +1278,16 @@ uiLayout *uiTemplateGroup(uiLayout *layout, Object *ob, Group *group)
 
 #define B_MATPRV 1
 
+
+static void do_preview_buttons(bContext *C, void *arg, int event)
+{
+	switch(event) {
+		case B_MATPRV:
+			WM_event_add_notifier(C, NC_MATERIAL|ND_SHADING, arg);
+			break;
+	}
+}
+
 void uiTemplatePreview(uiLayout *layout, ID *id)
 {
 	uiLayout *row, *col;
@@ -1294,8 +1305,12 @@ void uiTemplatePreview(uiLayout *layout, ID *id)
 
 	col= uiLayoutColumn(row, 0);
 	uiLayoutSetKeepAspect(col, 1);
-	uiDefBut(block, ROUNDBOX, 0, "", 0, 0, UI_UNIT_X*6, UI_UNIT_Y*6, NULL, 0.0, 0.0, 0, 0, "");
-
+	uiDefBut(block, ROUNDBOX, 0, "", 0, 0, UI_UNIT_X*6, UI_UNIT_Y*6, id, 0.0, 0.0, 0, 0, "");
+	/* extra draw is tied to roundbox for now */
+	uiBlockSetDrawExtraFunc(block, ED_preview_draw);
+	
+	uiBlockSetHandleFunc(block, do_preview_buttons, NULL);
+	
 	if(GS(id->name) == ID_MA) {
 		ma= (Material*)id;