[Bf-blender-cvs] [c76141e425a] master: UI: Adding Constraint to the Area Join Operations

[Harley Acheson]

Commit: c76141e425aaeb14af6f8f9c62f78545fc4270f2
Author: Harley Acheson
Date:   Sun Apr 25 17:55:00 2021 -0700
Branches: master
https://developer.blender.org/rBc76141e425aaeb14af6f8f9c62f78545fc4270f2

UI: Adding Constraint to the Area Join Operations

Removing mid-operation area re-targeting for safety and predictability.

Differential Revision: https://developer.blender.org/D11066

Reviewed by Campbell Barton

===================================================================

M	source/blender/editors/screen/screen_ops.c

===================================================================

diff --git a/source/blender/editors/screen/screen_ops.c b/source/blender/editors/screen/screen_ops.c
index cc920aece0a..5b371ed2caa 100644
--- a/source/blender/editors/screen/screen_ops.c
+++ b/source/blender/editors/screen/screen_ops.c
@@ -3262,8 +3262,9 @@ static void SCREEN_OT_screen_full_area(wmOperatorType *ot)
  */
 
 typedef struct sAreaJoinData {
-  ScrArea *sa1;        /* first area to be considered */
-  ScrArea *sa2;        /* second area to be considered */
+  ScrArea *sa1;        /* Potential source area (kept). */
+  ScrArea *sa2;        /* Potential target area (removed or reduced). */
+  int dir;             /* Direction of potential join. */
   void *draw_callback; /* call 'ED_screen_draw_join_highlight' */
 
 } sAreaJoinData;
@@ -3273,7 +3274,7 @@ static void area_join_draw_cb(const struct wmWindow *UNUSED(win), void *userdata
   const wmOperator *op = userdata;
 
   sAreaJoinData *sd = op->customdata;
-  if (sd->sa1 && sd->sa2) {
+  if (sd->sa1 && sd->sa2 && (sd->dir != -1)) {
     ED_screen_draw_join_highlight(sd->sa1, sd->sa2);
   }
 }
@@ -3296,6 +3297,7 @@ static bool area_join_init(bContext *C, wmOperator *op, ScrArea *sa1, ScrArea *s
 
   jd->sa1 = sa1;
   jd->sa2 = sa2;
+  jd->dir = -1;
 
   op->customdata = jd;
 
@@ -3308,7 +3310,7 @@ static bool area_join_init(bContext *C, wmOperator *op, ScrArea *sa1, ScrArea *s
 static bool area_join_apply(bContext *C, wmOperator *op)
 {
   sAreaJoinData *jd = (sAreaJoinData *)op->customdata;
-  if (!jd) {
+  if (!jd || (jd->dir == -1)) {
     return false;
   }
 
@@ -3410,61 +3412,30 @@ static int area_join_modal(bContext *C, wmOperator *op, const wmEvent *event)
 
     case MOUSEMOVE: {
       ScrArea *area = BKE_screen_find_area_xy(screen, SPACE_TYPE_ANY, event->x, event->y);
-      int dir = -1;
+      jd->dir = area_getorientation(jd->sa1, jd->sa2);
 
-      if (area) {
-        if (jd->sa1 != area) {
-          dir = area_getorientation(jd->sa1, area);
-          if (dir != -1) {
-            jd->sa2 = area;
-          }
-          else {
-            /* we are not bordering on the previously selected area
-             * we check if area has common border with the one marked for removal
-             * in this case we can swap areas.
-             */
-            dir = area_getorientation(area, jd->sa2);
-            if (dir != -1) {
-              jd->sa1 = jd->sa2;
-              jd->sa2 = area;
-            }
-            else {
-              jd->sa2 = NULL;
-            }
-          }
-          WM_event_add_notifier(C, NC_WINDOW, NULL);
-        }
-        else {
-          /* we are back in the area previously selected for keeping
-           * we swap the areas if possible to allow user to choose */
-          if (jd->sa2 != NULL) {
-            jd->sa1 = jd->sa2;
-            jd->sa2 = area;
-            dir = area_getorientation(jd->sa1, jd->sa2);
-            if (dir == -1) {
-              printf("oops, didn't expect that!\n");
-            }
-          }
-          else {
-            dir = area_getorientation(jd->sa1, area);
-            if (dir != -1) {
-              jd->sa2 = area;
-            }
-          }
-          WM_event_add_notifier(C, NC_WINDOW, NULL);
-        }
+      if (area == jd->sa1) {
+        /* Hovering current source, so change direction. */
+        jd->sa1 = jd->sa2;
+        jd->sa2 = area;
+        jd->dir = area_getorientation(jd->sa1, jd->sa2);
       }
+      else if (area != jd->sa2) {
+        jd->dir = -1;
+      }
+
+      WM_event_add_notifier(C, NC_WINDOW, NULL);
 
-      if (dir == 1) {
+      if (jd->dir == 1) {
         WM_cursor_set(win, WM_CURSOR_N_ARROW);
       }
-      else if (dir == 3) {
+      else if (jd->dir == 3) {
         WM_cursor_set(win, WM_CURSOR_S_ARROW);
       }
-      else if (dir == 2) {
+      else if (jd->dir == 2) {
         WM_cursor_set(win, WM_CURSOR_E_ARROW);
       }
-      else if (dir == 0) {
+      else if (jd->dir == 0) {
         WM_cursor_set(win, WM_CURSOR_W_ARROW);
       }
       else {
@@ -3475,6 +3446,10 @@ static int area_join_modal(bContext *C, wmOperator *op, const wmEvent *event)
     }
     case LEFTMOUSE:
       if (event->val == KM_RELEASE) {
+        if (jd->dir == -1) {
+          area_join_cancel(C, op);
+          return OPERATOR_CANCELLED;
+        }
         ED_area_tag_redraw(jd->sa1);
         ED_area_tag_redraw(jd->sa2);