WM: Application Templates

This adds the ability to switch between different application-configurations
without interfering with Blender's normal operation.

This commit doesn't include any templates,
so its mostly to allow collaboration for the Blender 101 project
and other custom configurations.

Application templates can be installed & selected from the file menu.

Other details:

- The `bl_app_template_utils` module handles template activation
  (similar to `addon_utils`).
- The `bl_app_override` module is a general module
  to assist scripts overriding parts of Blender in reversible way.

See docs:
https://docs.blender.org/manual/en/dev/advanced/app_templates.html

See patch: D2565

4 files changed, 194 insertions, 24 deletions

diff --git a/source/blender/windowmanager/intern/wm_files.c b/source/blender/windowmanager/intern/wm_files.c
index cff27dfc9e8..826cf490f53 100644
--- a/source/blender/windowmanager/intern/wm_files.c
+++ b/source/blender/windowmanager/intern/wm_files.c
@@ -470,6 +470,10 @@ static void wm_file_read_post(bContext *C, bool is_startup_file)
 	if (is_startup_file) {
 		/* possible python hasn't been initialized */
 		if (CTX_py_init_get(C)) {
+			/* Only run when we have a template path found. */
+			if (BKE_appdir_app_template_any()) {
+				BPY_execute_string(C, "__import__('bl_app_template_utils').reset()");
+			}
 			/* sync addons, these may have changed from the defaults */
 			BPY_execute_string(C, "__import__('addon_utils').reset_all()");
 
@@ -635,15 +639,23 @@ bool WM_file_read(bContext *C, const char *filepath, ReportList *reports)
  * \param use_factory_settings: Ignore on-disk startup file, use bundled ``datatoc_startup_blend`` instead.
  * Used for "Restore Factory Settings".
  * \param filepath_startup_override: Optional path pointing to an alternative blend file (may be NULL).
+ * \param app_template_override: Template to use instead of the template defined in user-preferences.
+ * When not-null, this is written into the user preferences.
  */
 int wm_homefile_read(
-        bContext *C, ReportList *reports,
-        bool use_factory_settings, const char *filepath_startup_override)
+        bContext *C, ReportList *reports, bool use_factory_settings,
+        const char *filepath_startup_override, const char *app_template_override)
 {
 	ListBase wmbase;
+	bool success = false;
+
 	char filepath_startup[FILE_MAX];
 	char filepath_userdef[FILE_MAX];
-	bool success = false;
+
+	/* When 'app_template' is set: '{BLENDER_USER_CONFIG}/{app_template}' */
+	char app_template_system[FILE_MAX];
+	/* When 'app_template' is set: '{BLENDER_SYSTEM_SCRIPTS}/startup/bl_app_templates_system/{app_template}' */
+	char app_template_config[FILE_MAX];
 
 	/* Indicates whether user preferences were really load from memory.
 	 *
@@ -675,12 +687,14 @@ int wm_homefile_read(
 
 	filepath_startup[0] = '\0';
 	filepath_userdef[0] = '\0';
+	app_template_system[0] = '\0';
+	app_template_config[0] = '\0';
 
+	const char * const cfgdir = BKE_appdir_folder_id(BLENDER_USER_CONFIG, NULL);
 	if (!use_factory_settings) {
-		const char * const cfgdir = BKE_appdir_folder_id(BLENDER_USER_CONFIG, NULL);
 		if (cfgdir) {
-			BLI_make_file_string("/", filepath_startup, cfgdir, BLENDER_STARTUP_FILE);
-			BLI_make_file_string("/", filepath_userdef, cfgdir, BLENDER_USERPREF_FILE);
+			BLI_path_join(filepath_startup, sizeof(filepath_startup), cfgdir, BLENDER_STARTUP_FILE, NULL);
+			BLI_path_join(filepath_userdef, sizeof(filepath_startup), cfgdir, BLENDER_USERPREF_FILE, NULL);
 		}
 		else {
 			use_factory_settings = true;
@@ -704,7 +718,43 @@ int wm_homefile_read(
 		}
 	}
 
-	if (!use_factory_settings) {
+	const char *app_template = NULL;
+
+	if (filepath_startup_override != NULL) {
+		/* pass */
+	}
+	else if (app_template_override) {
+		app_template = app_template_override;
+	}
+	else if (!use_factory_settings && U.app_template[0]) {
+		app_template = U.app_template;
+	}
+
+	if (app_template != NULL) {
+		BKE_appdir_app_template_id_search(app_template, app_template_system, sizeof(app_template_system));
+		BLI_path_join(app_template_config, sizeof(app_template_config), cfgdir, app_template, NULL);
+	}
+
+	/* insert template name into startup file */
+	if (app_template != NULL) {
+		/* note that the path is being set even when 'use_factory_settings == true'
+		 * this is done so we can load a templates factory-settings */
+		if (!use_factory_settings) {
+			BLI_path_join(filepath_startup, sizeof(filepath_startup), app_template_config, BLENDER_STARTUP_FILE, NULL);
+			if (BLI_access(filepath_startup, R_OK) != 0) {
+				filepath_startup[0] = '\0';
+			}
+		}
+		else {
+			filepath_startup[0] = '\0';
+		}
+
+		if (filepath_startup[0] == '\0') {
+			BLI_path_join(filepath_startup, sizeof(filepath_startup), app_template_system, BLENDER_STARTUP_FILE, NULL);
+		}
+	}
+
+	if (!use_factory_settings || (filepath_startup[0] != '\0')) {
 		if (BLI_access(filepath_startup, R_OK) == 0) {
 			success = (BKE_blendfile_read(C, filepath_startup, NULL, skip_flags) != BKE_BLENDFILE_READ_FAIL);
 		}
@@ -716,8 +766,8 @@ int wm_homefile_read(
 	}
 
 	if (success == false && filepath_startup_override && reports) {
+		/* We can not return from here because wm is already reset */
 		BKE_reportf(reports, RPT_ERROR, "Could not read '%s'", filepath_startup_override);
-		/*We can not return from here because wm is already reset*/
 	}
 
 	if (success == false) {
@@ -733,7 +783,45 @@ int wm_homefile_read(
 		U.flag |= USER_SCRIPT_AUTOEXEC_DISABLE;
 #endif
 	}
-	
+
+	/* Load template preferences,
+	 * unlike regular preferences we only use some of the settings,
+	 * see: BKE_blender_userdef_set_app_template */
+	if (app_template_system[0] != '\0') {
+		char temp_path[FILE_MAX];
+		temp_path[0] = '\0';
+		if (!use_factory_settings) {
+			BLI_path_join(temp_path, sizeof(temp_path), app_template_config, BLENDER_USERPREF_FILE, NULL);
+			if (BLI_access(temp_path, R_OK) != 0) {
+				temp_path[0] = '\0';
+			}
+		}
+
+		if (temp_path[0] == '\0') {
+			BLI_path_join(temp_path, sizeof(temp_path), app_template_system, BLENDER_USERPREF_FILE, NULL);
+		}
+
+		UserDef *userdef_template = NULL;
+		/* just avoids missing file warning */
+		if (BLI_exists(temp_path)) {
+			userdef_template = BKE_blendfile_userdef_read(temp_path, NULL);
+		}
+		if (userdef_template == NULL) {
+			/* we need to have preferences load to overwrite preferences from previous template */
+			userdef_template = BKE_blendfile_userdef_read_from_memory(
+					datatoc_startup_blend, datatoc_startup_blend_size, NULL);
+		}
+		if (userdef_template) {
+			BKE_blender_userdef_set_app_template(userdef_template);
+			BKE_blender_userdef_free_data(userdef_template);
+			MEM_freeN(userdef_template);
+		}
+	}
+
+	if (app_template_override) {
+		BLI_strncpy(U.app_template, app_template_override, sizeof(U.app_template));
+	}
+
 	/* prevent buggy files that had G_FILE_RELATIVE_REMAP written out by mistake. Screws up autosaves otherwise
 	 * can remove this eventually, only in a 2.53 and older, now its not written */
 	G.fileflags &= ~G_FILE_RELATIVE_REMAP;
@@ -1271,6 +1359,13 @@ static int wm_homefile_write_exec(bContext *C, wmOperator *op)
 	char filepath[FILE_MAX];
 	int fileflags;
 
+	const char *app_template = U.app_template[0] ? U.app_template : NULL;
+	const char * const cfgdir = BKE_appdir_folder_id_create(BLENDER_USER_CONFIG, app_template);
+	if (cfgdir == NULL) {
+		BKE_report(op->reports, RPT_ERROR, "Unable to create user config path");
+		return OPERATOR_CANCELLED;
+	}
+
 	BLI_callback_exec(G.main, NULL, BLI_CB_EVT_SAVE_PRE);
 
 	/* check current window and close it if temp */
@@ -1280,7 +1375,8 @@ static int wm_homefile_write_exec(bContext *C, wmOperator *op)
 	/* update keymaps in user preferences */
 	WM_keyconfig_update(wm);
 
-	BLI_make_file_string("/", filepath, BKE_appdir_folder_id_create(BLENDER_USER_CONFIG, NULL), BLENDER_STARTUP_FILE);
+	BLI_path_join(filepath, sizeof(filepath), cfgdir, BLENDER_STARTUP_FILE, NULL);
+
 	printf("trying to save homefile at %s ", filepath);
 
 	ED_editors_flush_edits(C, false);
@@ -1358,21 +1454,44 @@ static int wm_userpref_write_exec(bContext *C, wmOperator *op)
 {
 	wmWindowManager *wm = CTX_wm_manager(C);
 	char filepath[FILE_MAX];
+	const char *cfgdir;
+	bool ok = false;
 
 	/* update keymaps in user preferences */
 	WM_keyconfig_update(wm);
 
-	BLI_make_file_string("/", filepath, BKE_appdir_folder_id_create(BLENDER_USER_CONFIG, NULL), BLENDER_USERPREF_FILE);
-	printf("trying to save userpref at %s ", filepath);
-
-	if (BKE_blendfile_userdef_write(filepath, op->reports) == 0) {
-		printf("fail\n");
-		return OPERATOR_CANCELLED;
+	if ((cfgdir = BKE_appdir_folder_id_create(BLENDER_USER_CONFIG, NULL))) {
+		BLI_path_join(filepath, sizeof(filepath), cfgdir, BLENDER_USERPREF_FILE, NULL);
+		printf("trying to save userpref at %s ", filepath);
+		if (BKE_blendfile_userdef_write(filepath, op->reports) != 0) {
+			printf("ok\n");
+			ok = true;
+		}
+		else {
+			printf("fail\n");
+		}
+	}
+	else {
+		BKE_report(op->reports, RPT_ERROR, "Unable to create userpref path");
 	}
 
-	printf("ok\n");
+	if (U.app_template[0] && (cfgdir = BKE_appdir_folder_id_create(BLENDER_USER_CONFIG, U.app_template))) {
+		/* Also save app-template prefs */
+		BLI_path_join(filepath, sizeof(filepath), cfgdir, BLENDER_USERPREF_FILE, NULL);
+		printf("trying to save app-template userpref at %s ", filepath);
+		if (BKE_blendfile_userdef_write(filepath, op->reports) == 0) {
+			printf("fail\n");
+			ok = true;
+		}
+		else {
+			printf("ok\n");
+		}
+	}
+	else if (U.app_template[0]) {
+		BKE_report(op->reports, RPT_ERROR, "Unable to create app-template userpref path");
+	}
 
-	return OPERATOR_FINISHED;
+	return ok ? OPERATOR_FINISHED : OPERATOR_CANCELLED;
 }
 
 void WM_OT_save_userpref(wmOperatorType *ot)
@@ -1433,9 +1552,21 @@ static int wm_homefile_read_exec(bContext *C, wmOperator *op)
 		G.fileflags &= ~G_FILE_NO_UI;
 	}
 
-	if (wm_homefile_read(C, op->reports, use_factory_settings, filepath)) {
-		/* Load a file but keep the splash open */
-		if (!use_factory_settings && RNA_boolean_get(op->ptr, "use_splash")) {
+	char app_template_buf[sizeof(U.app_template)];
+	const char *app_template;
+	PropertyRNA *prop_app_template = RNA_struct_find_property(op->ptr, "app_template");
+	const bool use_splash = !use_factory_settings && RNA_boolean_get(op->ptr, "use_splash");
+
+	if (prop_app_template && RNA_property_is_set(op->ptr, prop_app_template)) {
+		RNA_property_string_get(op->ptr, prop_app_template, app_template_buf);
+		app_template = app_template_buf;
+	}
+	else {
+		app_template = NULL;
+	}
+
+	if (wm_homefile_read(C, op->reports, use_factory_settings, filepath, app_template)) {
+		if (use_splash) {
 			WM_init_splash(C);
 		}
 		return OPERATOR_FINISHED;
@@ -1469,17 +1600,26 @@ void WM_OT_read_homefile(wmOperatorType *ot)
 	prop = RNA_def_boolean(ot->srna, "use_splash", false, "Splash", "");
 	RNA_def_property_flag(prop, PROP_HIDDEN | PROP_SKIP_SAVE);
 
+	prop = RNA_def_string(ot->srna, "app_template", "Template", sizeof(U.app_template), "", "");
+	RNA_def_property_flag(prop, PROP_HIDDEN | PROP_SKIP_SAVE);
+
 	/* omit poll to run in background mode */
 }
 
 void WM_OT_read_factory_settings(wmOperatorType *ot)
 {
+	PropertyRNA *prop;
+
 	ot->name = "Load Factory Settings";
 	ot->idname = "WM_OT_read_factory_settings";
 	ot->description = "Load default file and user preferences";
 
 	ot->invoke = WM_operator_confirm;
 	ot->exec = wm_homefile_read_exec;
+
+	prop = RNA_def_string(ot->srna, "app_template", "Template", sizeof(U.app_template), "", "");
+	RNA_def_property_flag(prop, PROP_HIDDEN | PROP_SKIP_SAVE);
+
 	/* omit poll to run in background mode */
 }
 
diff --git a/source/blender/windowmanager/intern/wm_init_exit.c b/source/blender/windowmanager/intern/wm_init_exit.c
index be74a0c7362..5483cf25e40 100644
--- a/source/blender/windowmanager/intern/wm_init_exit.c
+++ b/source/blender/windowmanager/intern/wm_init_exit.c
@@ -192,7 +192,7 @@ void WM_init(bContext *C, int argc, const char **argv)
 	wm_init_reports(C);
 
 	/* get the default database, plus a wm */
-	wm_homefile_read(C, NULL, G.factory_startup, NULL);
+	wm_homefile_read(C, NULL, G.factory_startup, NULL, NULL);
 	
 
 	BLT_lang_set(NULL);
diff --git a/source/blender/windowmanager/intern/wm_operators.c b/source/blender/windowmanager/intern/wm_operators.c
index 841b63d4ab8..39e06ccc3c8 100644
--- a/source/blender/windowmanager/intern/wm_operators.c
+++ b/source/blender/windowmanager/intern/wm_operators.c
@@ -1762,6 +1762,36 @@ static uiBlock *wm_block_create_splash(bContext *C, ARegion *ar, void *UNUSED(ar
 		ibuf = IMB_ibImageFromMemory((unsigned char *)datatoc_splash_png,
 		                             datatoc_splash_png_size, IB_rect, NULL, "<splash screen>");
 	}
+
+	/* overwrite splash with template image */
+	if (U.app_template[0] != '\0') {
+		ImBuf *ibuf_template = NULL;
+		char splash_filepath[FILE_MAX];
+		char template_directory[FILE_MAX];
+
+		if (BKE_appdir_app_template_id_search(
+		        U.app_template,
+		        template_directory, sizeof(template_directory)))
+		{
+			BLI_join_dirfile(
+			        splash_filepath, sizeof(splash_filepath), template_directory,
+			        (U.pixelsize == 2) ? "splash_2x.png" : "splash.png");
+			ibuf_template = IMB_loadiffname(splash_filepath, IB_rect, NULL);
+			if (ibuf_template) {
+				const int x_expect = ibuf_template->x;
+				const int y_expect = 230 * (int)U.pixelsize;
+				/* don't cover the header text */
+				if (ibuf_template->x == x_expect && ibuf_template->y == y_expect) {
+					memcpy(ibuf->rect, ibuf_template->rect, ibuf_template->x * ibuf_template->y * sizeof(char[4]));
+				}
+				else {
+					printf("Splash expected %dx%d found %dx%d, ignoring: %s\n",
+					       x_expect, y_expect, ibuf_template->x, ibuf_template->y, splash_filepath);
+				}
+				IMB_freeImBuf(ibuf_template);
+			}
+		}
+	}
 #endif
 
 	block = UI_block_begin(C, ar, "_popup", UI_EMBOSS);
diff --git a/source/blender/windowmanager/wm_files.h b/source/blender/windowmanager/wm_files.h
index 048b5a997bb..15a94d2da70 100644
--- a/source/blender/windowmanager/wm_files.h
+++ b/source/blender/windowmanager/wm_files.h
@@ -36,8 +36,8 @@ struct wmOperatorType;
 /* wm_files.c */
 void		wm_history_file_read(void);
 int			wm_homefile_read(
-        struct bContext *C, struct ReportList *reports,
-        bool use_factory_settings, const char *filepath_startup_override);
+        struct bContext *C, struct ReportList *reports, bool use_factory_settings,
+        const char *filepath_startup_override, const char *app_template_override);
 void		wm_file_read_report(bContext *C);
 
 void        WM_OT_save_homefile(struct wmOperatorType *ot);