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

10 files changed, 288 insertions, 25 deletions

diff --git a/source/blender/blenkernel/BKE_appdir.h b/source/blender/blenkernel/BKE_appdir.h
index c6587b94666..ac8f861fa56 100644
--- a/source/blender/blenkernel/BKE_appdir.h
+++ b/source/blender/blenkernel/BKE_appdir.h
@@ -33,6 +33,9 @@ const char *BKE_appdir_folder_id_create(const int folder_id, const char *subfold
 const char *BKE_appdir_folder_id_user_notest(const int folder_id, const char *subfolder);
 const char *BKE_appdir_folder_id_version(const int folder_id, const int ver, const bool do_check);
 
+bool BKE_appdir_app_template_any(void);
+bool BKE_appdir_app_template_id_search(const char *app_template, char *path, size_t path_len);
+
 /* Initialize path to program executable */
 void        BKE_appdir_program_path_init(const char *argv0);
 
diff --git a/source/blender/blenkernel/BKE_blender.h b/source/blender/blenkernel/BKE_blender.h
index 62a15bae153..d55926ffb1e 100644
--- a/source/blender/blenkernel/BKE_blender.h
+++ b/source/blender/blenkernel/BKE_blender.h
@@ -52,6 +52,8 @@ void BKE_blender_userdef_set_data(struct UserDef *userdef);
 void BKE_blender_userdef_free_data(struct UserDef *userdef);
 void BKE_blender_userdef_refresh(void);
 
+void BKE_blender_userdef_set_app_template(struct UserDef *userdef);
+
 /* set this callback when a UI is running */
 void BKE_blender_callback_test_break_set(void (*func)(void));
 int  BKE_blender_test_break(void);
diff --git a/source/blender/blenkernel/intern/appdir.c b/source/blender/blenkernel/intern/appdir.c
index 3fb8a147960..43fd47981b1 100644
--- a/source/blender/blenkernel/intern/appdir.c
+++ b/source/blender/blenkernel/intern/appdir.c
@@ -683,6 +683,48 @@ bool BKE_appdir_program_python_search(
 	return is_found;
 }
 
+static const char *app_template_directory_search[2] = {
+	"startup" SEP_STR "bl_app_templates_user",
+	"startup" SEP_STR "bl_app_templates_system",
+};
+
+static const int app_template_directory_id[2] = {
+	BLENDER_USER_SCRIPTS,
+	BLENDER_SYSTEM_SCRIPTS,
+};
+
+/**
+ * Return true if templates exist
+ */
+bool BKE_appdir_app_template_any(void)
+{
+	char temp_dir[FILE_MAX];
+	for (int i = 0; i < 2; i++) {
+		if (BKE_appdir_folder_id_ex(
+		        app_template_directory_id[i], app_template_directory_search[i],
+		        temp_dir, sizeof(temp_dir)))
+		{
+			return true;
+		}
+	}
+	return false;
+}
+
+bool BKE_appdir_app_template_id_search(const char *app_template, char *path, size_t path_len)
+{
+	for (int i = 0; i < 2; i++) {
+		char subdir[FILE_MAX];
+		BLI_join_dirfile(subdir, sizeof(subdir), app_template_directory_search[i], app_template);
+		if (BKE_appdir_folder_id_ex(
+		        app_template_directory_id[i], subdir,
+		        path, path_len))
+		{
+			return true;
+		}
+	}
+	return false;
+}
+
 /**
  * Gets the temp directory when blender first runs.
  * If the default path is not found, use try $TEMP
diff --git a/source/blender/blenkernel/intern/blender.c b/source/blender/blenkernel/intern/blender.c
index f661f18fbc0..ceb641073e0 100644
--- a/source/blender/blenkernel/intern/blender.c
+++ b/source/blender/blenkernel/intern/blender.c
@@ -238,6 +238,44 @@ void BKE_blender_userdef_refresh(void)
 
 }
 
+/**
+ * Write U from userdef.
+ * This function defines which settings a template will override for the user preferences.
+ */
+void BKE_blender_userdef_set_app_template(UserDef *userdef)
+{
+	/* TODO:
+	 * - keymaps
+	 * - various minor settings (add as needed).
+	 */
+
+#define LIST_OVERRIDE(id) { \
+	BLI_freelistN(&U.id); \
+	BLI_movelisttolist(&U.id, &userdef->id); \
+} ((void)0)
+
+#define MEMCPY_OVERRIDE(id) \
+	memcpy(U.id, userdef->id, sizeof(U.id));
+
+	/* for some types we need custom free functions */
+	userdef_free_addons(&U);
+	userdef_free_keymaps(&U);
+
+	LIST_OVERRIDE(uistyles);
+	LIST_OVERRIDE(uifonts);
+	LIST_OVERRIDE(themes);
+	LIST_OVERRIDE(addons);
+	LIST_OVERRIDE(user_keymaps);
+
+	MEMCPY_OVERRIDE(light);
+
+	MEMCPY_OVERRIDE(font_path_ui);
+	MEMCPY_OVERRIDE(font_path_ui_mono);
+
+#undef LIST_OVERRIDE
+#undef MEMCPY_OVERRIDE
+}
+
 /* *****************  testing for break ************* */
 
 static void (*blender_test_break_cb)(void) = NULL;
diff --git a/source/blender/makesdna/DNA_userdef_types.h b/source/blender/makesdna/DNA_userdef_types.h
index 73c341e35ba..d76452edb83 100644
--- a/source/blender/makesdna/DNA_userdef_types.h
+++ b/source/blender/makesdna/DNA_userdef_types.h
@@ -473,7 +473,10 @@ typedef struct UserDef {
 	char pad2;
 	short transopts;
 	short menuthreshold1, menuthreshold2;
-	
+
+	/* startup template */
+	char app_template[64];
+
 	struct ListBase themes;
 	struct ListBase uifonts;
 	struct ListBase uistyles;
diff --git a/source/blender/makesrna/intern/rna_userdef.c b/source/blender/makesrna/intern/rna_userdef.c
index 74888bf4f00..7b6eb5fef47 100644
--- a/source/blender/makesrna/intern/rna_userdef.c
+++ b/source/blender/makesrna/intern/rna_userdef.c
@@ -4678,6 +4678,11 @@ void RNA_def_userdef(BlenderRNA *brna)
 	                         "Active section of the user preferences shown in the user interface");
 	RNA_def_property_update(prop, 0, "rna_userdef_update");
 
+	/* don't expose this directly via the UI, modify via an operator */
+	prop = RNA_def_property(srna, "app_template", PROP_STRING, PROP_NONE);
+	RNA_def_property_string_sdna(prop, NULL, "app_template");
+	RNA_def_property_ui_text(prop, "Application Template", "");
+
 	prop = RNA_def_property(srna, "themes", PROP_COLLECTION, PROP_NONE);
 	RNA_def_property_collection_sdna(prop, NULL, "themes", NULL);
 	RNA_def_property_struct_type(prop, "Theme");
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);