File Browser: Refactor access to the selection parameters struct

* Avoid direct access to `SpaceFile.params`, use a getter instead. This matters
  because once the asset-browser changes are in, there will be an alternative
  selection parameter object. The getter can return the correct one.
* Rename the function to ensure the parameters. The old name
  `ED_fileselect_get_params()` wasn't a mere getter, it would create the
  parameters if necessary. Now we have an actual getter, so better be clear.
* In some instances, I replaced the old "get" function with the new mere
  getter. So the ensure logic is called less often. However, in these cases we
  should be able to assume the selection parameters were created already as
  part of the editor creation routine.

The term "active" in the new function names may seem a bit odd in the current
context, but that is a preparation for the Asset Browser merge as well. Like
said, there will be two file selection parameter objects in the space.

1 files changed, 56 insertions, 48 deletions

diff --git a/source/blender/editors/space_file/filesel.c b/source/blender/editors/space_file/filesel.c
index 15c6972c5f5..ffa44083473 100644
--- a/source/blender/editors/space_file/filesel.c
+++ b/source/blender/editors/space_file/filesel.c
@@ -77,18 +77,20 @@
 
 #define VERTLIST_MAJORCOLUMN_WIDTH (25 * UI_UNIT_X)
 
-FileSelectParams *ED_fileselect_get_params(struct SpaceFile *sfile)
+FileSelectParams *ED_fileselect_get_active_params(const SpaceFile *sfile)
 {
-  if (!sfile->params) {
-    ED_fileselect_set_params(sfile);
+  if (!sfile) {
+    /* Sometimes called in poll before space type was checked. */
+    return NULL;
   }
+
   return sfile->params;
 }
 
 /**
  * \note RNA_struct_property_is_set_ex is used here because we want
  *       the previously used settings to be used here rather than overriding them */
-short ED_fileselect_set_params(SpaceFile *sfile)
+static void fileselect_ensure_file_params(SpaceFile *sfile)
 {
   FileSelectParams *params;
   wmOperator *op = sfile->op;
@@ -136,20 +138,17 @@ short ED_fileselect_set_params(SpaceFile *sfile)
       RNA_string_get(op->ptr, "filepath", name);
       if (params->type == FILE_LOADLIB) {
         BLI_strncpy(params->dir, name, sizeof(params->dir));
-        sfile->params->file[0] = '\0';
+        params->file[0] = '\0';
       }
       else {
-        BLI_split_dirfile(name,
-                          sfile->params->dir,
-                          sfile->params->file,
-                          sizeof(sfile->params->dir),
-                          sizeof(sfile->params->file));
+        BLI_split_dirfile(
+            name, params->dir, params->file, sizeof(params->dir), sizeof(params->file));
       }
     }
     else {
       if (is_directory && RNA_struct_property_is_set_ex(op->ptr, "directory", false)) {
         RNA_string_get(op->ptr, "directory", params->dir);
-        sfile->params->file[0] = '\0';
+        params->file[0] = '\0';
       }
 
       if (is_filename && RNA_struct_property_is_set_ex(op->ptr, "filename", false)) {
@@ -306,26 +305,32 @@ short ED_fileselect_set_params(SpaceFile *sfile)
     sfile->folders_prev = folderlist_new();
   }
 
-  if (!sfile->params->dir[0]) {
+  if (!params->dir[0]) {
     if (blendfile_path[0] != '\0') {
-      BLI_split_dir_part(blendfile_path, sfile->params->dir, sizeof(sfile->params->dir));
+      BLI_split_dir_part(blendfile_path, params->dir, sizeof(params->dir));
     }
     else {
       const char *doc_path = BKE_appdir_folder_default();
       if (doc_path) {
-        BLI_strncpy(sfile->params->dir, doc_path, sizeof(sfile->params->dir));
+        BLI_strncpy(params->dir, doc_path, sizeof(params->dir));
       }
     }
   }
 
-  folderlist_pushdir(sfile->folders_prev, sfile->params->dir);
+  folderlist_pushdir(sfile->folders_prev, params->dir);
 
   /* Switching thumbnails needs to recalc layout T28809. */
   if (sfile->layout) {
     sfile->layout->dirty = true;
   }
+}
 
-  return 1;
+FileSelectParams *ED_fileselect_ensure_active_params(SpaceFile *sfile)
+{
+  if (!sfile->params) {
+    fileselect_ensure_file_params(sfile);
+  }
+  return sfile->params;
 }
 
 /* The subset of FileSelectParams.flag items we store into preferences. Note that FILE_SORT_ALPHA
@@ -364,28 +369,26 @@ void ED_fileselect_set_params_from_userdef(SpaceFile *sfile)
   wmOperator *op = sfile->op;
   UserDef_FileSpaceData *sfile_udata = &U.file_space_data;
 
-  ED_fileselect_set_params(sfile);
-
+  FileSelectParams *params = ED_fileselect_ensure_active_params(sfile);
   if (!op) {
     return;
   }
 
-  sfile->params->thumbnail_size = sfile_udata->thumbnail_size;
-  sfile->params->details_flags = sfile_udata->details_flags;
-  sfile->params->filter_id = sfile_udata->filter_id;
+  params->thumbnail_size = sfile_udata->thumbnail_size;
+  params->details_flags = sfile_udata->details_flags;
+  params->filter_id = sfile_udata->filter_id;
 
   /* Combine flags we take from params with the flags we take from userdef. */
-  sfile->params->flag = (sfile->params->flag & ~PARAMS_FLAGS_REMEMBERED) |
-                        (sfile_udata->flag & PARAMS_FLAGS_REMEMBERED);
+  params->flag = (params->flag & ~PARAMS_FLAGS_REMEMBERED) |
+                 (sfile_udata->flag & PARAMS_FLAGS_REMEMBERED);
 
   if (file_select_use_default_display_type(sfile)) {
-    sfile->params->display = sfile_udata->display_type;
+    params->display = sfile_udata->display_type;
   }
   if (file_select_use_default_sort_type(sfile)) {
-    sfile->params->sort = sfile_udata->sort_type;
+    params->sort = sfile_udata->sort_type;
     /* For the default sorting, also take invert flag from userdef. */
-    sfile->params->flag = (sfile->params->flag & ~FILE_SORT_INVERT) |
-                          (sfile_udata->flag & FILE_SORT_INVERT);
+    params->flag = (params->flag & ~FILE_SORT_INVERT) | (sfile_udata->flag & FILE_SORT_INVERT);
   }
 }
 
@@ -400,25 +403,26 @@ void ED_fileselect_params_to_userdef(SpaceFile *sfile,
                                      const int temp_win_size[2],
                                      const bool is_maximized)
 {
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
   UserDef_FileSpaceData *sfile_udata_new = &U.file_space_data;
   UserDef_FileSpaceData sfile_udata_old = U.file_space_data;
 
-  sfile_udata_new->thumbnail_size = sfile->params->thumbnail_size;
-  sfile_udata_new->details_flags = sfile->params->details_flags;
-  sfile_udata_new->flag = sfile->params->flag & PARAMS_FLAGS_REMEMBERED;
-  sfile_udata_new->filter_id = sfile->params->filter_id;
+  sfile_udata_new->thumbnail_size = params->thumbnail_size;
+  sfile_udata_new->details_flags = params->details_flags;
+  sfile_udata_new->flag = params->flag & PARAMS_FLAGS_REMEMBERED;
+  sfile_udata_new->filter_id = params->filter_id;
 
   /* In some rare cases, operators ask for a specific display or sort type (e.g. chronological
    * sorting for "Recover Auto Save"). So the settings are optimized for a specific operation.
    * Don't let that change the userdef memory for more general cases. */
   if (file_select_use_default_display_type(sfile)) {
-    sfile_udata_new->display_type = sfile->params->display;
+    sfile_udata_new->display_type = params->display;
   }
   if (file_select_use_default_sort_type(sfile)) {
-    sfile_udata_new->sort_type = sfile->params->sort;
+    sfile_udata_new->sort_type = params->sort;
     /* In this case also remember the invert flag. */
     sfile_udata_new->flag = (sfile_udata_new->flag & ~FILE_SORT_INVERT) |
-                            (sfile->params->flag & FILE_SORT_INVERT);
+                            (params->flag & FILE_SORT_INVERT);
   }
 
   if (temp_win_size && !is_maximized) {
@@ -434,10 +438,11 @@ void ED_fileselect_params_to_userdef(SpaceFile *sfile,
 
 void ED_fileselect_reset_params(SpaceFile *sfile)
 {
-  sfile->params->type = FILE_UNIX;
-  sfile->params->flag = 0;
-  sfile->params->title[0] = '\0';
-  sfile->params->active_file = -1;
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
+  params->type = FILE_UNIX;
+  params->flag = 0;
+  params->title[0] = '\0';
+  params->active_file = -1;
 }
 
 /**
@@ -447,7 +452,8 @@ void fileselect_file_set(SpaceFile *sfile, const int index)
 {
   const struct FileDirEntry *file = filelist_file(sfile->files, index);
   if (file && file->relpath && file->relpath[0] && !(file->typeflag & FILE_TYPE_DIR)) {
-    BLI_strncpy(sfile->params->file, file->relpath, FILE_MAXFILE);
+    FileSelectParams *params = ED_fileselect_get_active_params(sfile);
+    BLI_strncpy(params->file, file->relpath, FILE_MAXFILE);
   }
 }
 
@@ -759,7 +765,7 @@ static void file_attribute_columns_init(const FileSelectParams *params, FileLayo
 
 void ED_fileselect_init_layout(struct SpaceFile *sfile, ARegion *region)
 {
-  FileSelectParams *params = ED_fileselect_get_params(sfile);
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
   FileLayout *layout = NULL;
   View2D *v2d = &region->v2d;
   int numfiles;
@@ -873,7 +879,8 @@ void ED_file_change_dir_ex(bContext *C, bScreen *screen, ScrArea *area)
     return;
   }
   SpaceFile *sfile = area->spacedata.first;
-  if (sfile->params) {
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
+  if (params) {
     wmWindowManager *wm = CTX_wm_manager(C);
     Scene *scene = WM_windows_scene_get_from_screen(wm, screen);
     if (LIKELY(scene != NULL)) {
@@ -882,20 +889,20 @@ void ED_file_change_dir_ex(bContext *C, bScreen *screen, ScrArea *area)
 
     /* Clear search string, it is very rare to want to keep that filter while changing dir,
      * and usually very annoying to keep it actually! */
-    sfile->params->filter_search[0] = '\0';
-    sfile->params->active_file = -1;
+    params->filter_search[0] = '\0';
+    params->active_file = -1;
 
-    if (!filelist_is_dir(sfile->files, sfile->params->dir)) {
-      BLI_strncpy(sfile->params->dir, filelist_dir(sfile->files), sizeof(sfile->params->dir));
+    if (!filelist_is_dir(sfile->files, params->dir)) {
+      BLI_strncpy(params->dir, filelist_dir(sfile->files), sizeof(params->dir));
       /* could return but just refresh the current dir */
     }
-    filelist_setdir(sfile->files, sfile->params->dir);
+    filelist_setdir(sfile->files, params->dir);
 
     if (folderlist_clear_next(sfile)) {
       folderlist_free(sfile->folders_next);
     }
 
-    folderlist_pushdir(sfile->folders_prev, sfile->params->dir);
+    folderlist_pushdir(sfile->folders_prev, params->dir);
 
     file_draw_check_ex(C, area);
   }
@@ -1010,7 +1017,8 @@ void ED_fileselect_clear(wmWindowManager *wm, Scene *owner_scene, SpaceFile *sfi
     filelist_clear(sfile->files);
   }
 
-  sfile->params->highlight_file = -1;
+  FileSelectParams *params = ED_fileselect_get_active_params(sfile);
+  params->highlight_file = -1;
   WM_main_add_notifier(NC_SPACE | ND_SPACE_FILE_LIST, NULL);
 }