UI: Preferences Redesign Part 2

(Part 1 was 00963afc14978b)

Does the following changes visible to users:
* Use panels and sub-panels for more structured & logical grouping
* Re-organized options more logically than before (see images in D4148)
* Use flow layout (single column by default).
* New layout uses horizontal margin if there's enough space.
* Change size of Preferences window to suit new layout.
* Move keymap related options from "Input" into own section.
* Own, left-bottom aligned region for Save Preferences button.
* Adjustments of names, tooltips & icons.
* Move buttons from header into the main region (except editor switch).
* Hide Preferences header when opened in temporary window.
* Use full area width for header.
* Don't use slider but regular number widget for UI scale.
* Gray out animation player path option if player isn't "Custom"

Internal changes:
* Rearrange RNA properties to match changed UI structure.
* Introduces new "EXECUTE" region type, see reasoning in D3982.
* Changes to panel layout and AZone code for dynamic panel region.
* Bumps subversion and does versioning for new regions.

RNA changes are documented in the release notes:
https://wiki.blender.org/wiki/Reference/Release_Notes/2.80/Python_API/Preferences_API

Design & implementation mostly done by @billreynish and myself.
I recommend checking out the screenshots posted by William:
https://developer.blender.org/D4148#93787

Reviewed By: brecht

Maniphest Tasks: T54115

Differential Revision: https://developer.blender.org/D4148

1 files changed, 45 insertions, 6 deletions

diff --git a/source/blender/editors/screen/screen_ops.c b/source/blender/editors/screen/screen_ops.c
index d41bf8d937b..62b4db94937 100644
--- a/source/blender/editors/screen/screen_ops.c
+++ b/source/blender/editors/screen/screen_ops.c
@@ -798,6 +798,32 @@ static AZone *area_actionzone_refresh_xy(ScrArea *sa, const int xy[2], const boo
 				}
 			}
 		}
+		else if (!test_only && !IS_EQF(az->alpha, 0.0f)) {
+			bool changed = false;
+
+			if (az->type == AZONE_FULLSCREEN) {
+				az->alpha = 0.0f;
+				changed = true;
+			}
+			else if (az->type == AZONE_REGION_SCROLL) {
+				if (az->direction == AZ_SCROLL_VERT) {
+					az->alpha = az->ar->v2d.alpha_vert = 0;
+					changed = true;
+				}
+				else if (az->direction == AZ_SCROLL_HOR) {
+					az->alpha = az->ar->v2d.alpha_hor = 0;
+					changed = true;
+				}
+				else {
+					BLI_assert(0);
+				}
+			}
+
+			if (changed) {
+				sa->flag &= ~AREA_FLAG_ACTIONZONES_UPDATE;
+				ED_area_tag_redraw_no_rebuild(sa);
+			}
+		}
 	}
 
 	return az;
@@ -808,7 +834,7 @@ AZone *ED_area_actionzone_find_xy(ScrArea *sa, const int xy[2])
 	return area_actionzone_refresh_xy(sa, xy, true);
 }
 
-AZone *ED_area_actionzone_refresh_xy(ScrArea *sa, const int xy[2])
+AZone *ED_area_azones_update(ScrArea *sa, const int xy[2])
 {
 	return area_actionzone_refresh_xy(sa, xy, false);
 }
@@ -2382,8 +2408,12 @@ static int region_scale_modal(bContext *C, wmOperator *op, const wmEvent *event)
 					if (!(rmd->ar->flag & RGN_FLAG_HIDDEN))
 						region_scale_toggle_hidden(C, rmd);
 				}
-				else if (rmd->ar->flag & RGN_FLAG_HIDDEN)
+				else if (rmd->ar->flag & RGN_FLAG_HIDDEN) {
 					region_scale_toggle_hidden(C, rmd);
+				}
+				else if (rmd->ar->flag & RGN_FLAG_DYNAMIC_SIZE) {
+					rmd->ar->sizex = rmd->origval;
+				}
 			}
 			else {
 				int maxsize = region_scale_get_maxsize(rmd);
@@ -2411,10 +2441,15 @@ static int region_scale_modal(bContext *C, wmOperator *op, const wmEvent *event)
 					if (!(rmd->ar->flag & RGN_FLAG_HIDDEN))
 						region_scale_toggle_hidden(C, rmd);
 				}
-				else if (maxsize > 0 && (rmd->ar->sizey > maxsize))
+				else if (maxsize > 0 && (rmd->ar->sizey > maxsize)) {
 					rmd->ar->sizey = maxsize;
-				else if (rmd->ar->flag & RGN_FLAG_HIDDEN)
+				}
+				else if (rmd->ar->flag & RGN_FLAG_HIDDEN) {
 					region_scale_toggle_hidden(C, rmd);
+				}
+				else if (rmd->ar->flag & RGN_FLAG_DYNAMIC_SIZE) {
+					rmd->ar->sizey = rmd->origval;
+				}
 			}
 			ED_area_tag_redraw(rmd->sa);
 			WM_event_add_notifier(C, NC_SCREEN | NA_EDITED, NULL);
@@ -4349,11 +4384,15 @@ static void SCREEN_OT_back_to_previous(struct wmOperatorType *ot)
 
 static int userpref_show_invoke(bContext *C, wmOperator *op, const wmEvent *event)
 {
-	int sizex = (800 + UI_NAVIGATION_REGION_WIDTH) * UI_DPI_FAC;
-	int sizey = 500 * UI_DPI_FAC;
+	int sizex = (500 + UI_NAVIGATION_REGION_WIDTH) * UI_DPI_FAC;
+	int sizey = 520 * UI_DPI_FAC;
 
 	/* changes context! */
 	if (WM_window_open_temp(C, event->x, event->y, sizex, sizey, WM_WINDOW_USERPREFS) != NULL) {
+		/* The header only contains the editor switcher and looks empty. So hiding in the temp window makes sense. */
+		ScrArea *area = CTX_wm_area(C);
+		ARegion *region = BKE_area_find_region_type(area, RGN_TYPE_HEADER);
+		region->flag |= RGN_FLAG_HIDDEN;
 		return OPERATOR_FINISHED;
 	}
 	else {