Added support for xrdb

evoke/Xsm.cpp

@@ -14,19 +14,172 @@
 #include <edelib/Debug.h>
 #include <edelib/TiXml.h>
 #include <edelib/File.h>
+#include <edelib/Color.h>
+#include <edelib/String.h>
+#include <edelib/Util.h>
+#include <edelib/Directory.h>
+#include <edelib/XSettingsCommon.h>
 #include <string.h>
 #include <limits.h>
 
+#include <FL/x.h>
+
+#include <X11/Xresource.h>
+
+#define USER_XRESOURCE       ".Xdefaults"
+#define USER_XRESOURCE_TMP   ".Xdefaults-tmp"
+#define USER_XRESOURCE_SAVED ".Xdefaults-ede-saved"
+
+struct ResourceMap {
+	char* name;
+	char* xresource_key;
+	char* xresource_klass;
+};
+
+/*
+ * Make sure xresource_klass with '*' is listed last since it have
+ * highest priority and will override all previous classes (X Resource class, not C++ one :P)
+ * with the same xresource_key.
+ */
+ResourceMap resource_map [] = {
+	{ "Fltk/Background2", "background", "*Text" },
+	{ "Fltk/Background",  "background", "*" },
+	{ "Fltk/Foreground",  "foreground", "*" }
+};
+
+#define RESOURCE_MAP_SIZE(x) (sizeof(x)/sizeof(x[0]))
+
 int ignore_xerrors(Display* display, XErrorEvent* xev) {
 	return True;
 }
 
-Xsm::Xsm() { }
+Xsm::Xsm() {
+}
 
 Xsm::~Xsm() { 
 	EDEBUG("Xsm::~Xsm()\n"); 
 }
 
+/*
+ * This is a short explaination how evoke's XSETTINGS part is combined
+ * with X Resource database (xrdb). First of all, why mess with this? Almost
+ * all pure X apps (xterm, xedit, rxvt) reads color (and more) from xrdb, not to say
+ * that FLTK apps do that too, at least those not linked with edelib::Window. On other
+ * hand since edelib::Window already have builtin XSETTINGS and FLTK backend, you will
+ * that colors for edelib::Window will be specified twice, but this is not a big deal
+ * since painting is done only once.
+ *
+ * Here, in the code, we look for XSETTINGS names listed in resource_map[] and they should 
+ * be colors only; when they are found, their equivalents will be created in xrdb as class/key 
+ * (see X Resource manual about these).
+ *
+ * Values picked up from XSETTINGS color items will be converted to html since because clients 
+ * who reads xrdb expects html colors (or X11 ones, like red/green/blue names, but let we not 
+ * complicate). After conversion, everything is stored in ~/.Xdefaults file. If this file
+ * already exists (someone else made it), it will be first merged, picking old values and backed up.
+ *
+ * After evoke quits, file is restored, if existed before or deleted if not. This is also a
+ * workaround for missing functions to delete key/value pairs from xrdb (what was they thinking for??).
+ */
+void Xsm::xresource_replace(void) {
+	// with inheritance we got manager_data
+	if(!manager_data->settings)
+		return;
+
+	edelib::String home = edelib::dir_home();
+
+	// try to open ~/.Xdefaults; if failed, X Resource will not complain
+	edelib::String db_file = edelib::build_filename("/", home.c_str(), USER_XRESOURCE);
+
+	// initialize XResource
+	XrmInitialize();
+	// load XResource database
+	XrmDatabase db = XrmGetFileDatabase(db_file.c_str());
+
+	edelib::XSettingsSetting* s;
+	int status;
+	char* type, *value;
+	XrmValue xrmv;
+	char color_val[8];
+
+	edelib::String tmp;
+
+	/* 
+	 * XSETTINGS does not contains duplicate entries so there is no need to 
+	 * check for them. We only scan ResourceMap table for XSETTINGS name and 
+	 * its X Resource equivalent.
+	 */
+	for(unsigned int i = 0; i < RESOURCE_MAP_SIZE(resource_map); i++) {
+		s = edelib::xsettings_list_find(manager_data->settings, resource_map[i].name);
+		if(!s)
+			continue;
+
+		// assure that XSETTINGS key is color type
+		if(s->type != edelib::XSETTINGS_TYPE_COLOR) {
+			EWARNING(ESTRLOC ": Expected color type in %s, but it is not, skipping...\n", s->name);
+			continue;
+		}
+
+		// check if resource is present
+		status = XrmGetResource(db, resource_map[i].xresource_key, resource_map[i].xresource_klass, &type, &xrmv);
+
+		if(status && strcmp(type, "String") == 0) {
+			EDEBUG(ESTRLOC ": %s.%s found in database\n", 
+					resource_map[i].xresource_klass, resource_map[i].xresource_key);
+
+			value = xrmv.addr;
+		}
+
+		/*
+		 * Now convert color from XSETTINGS to html value. First convert to fltk color.
+		 * TODO: Strange, didn't implemented something like color_rgb_to_html in edelib ?
+		 */
+		int fltk_color = edelib::color_rgb_to_fltk(s->data.v_color.red, s->data.v_color.green, s->data.v_color.blue);
+		edelib::color_fltk_to_html(fltk_color, color_val);
+
+		// and save it
+		tmp.clear();
+		tmp.printf("%s.%s: %s", resource_map[i].xresource_klass, resource_map[i].xresource_key, color_val);
+		XrmPutLineResource(&db, tmp.c_str());
+	}
+
+	edelib::String tmp_db_file = edelib::build_filename("/", home.c_str(), USER_XRESOURCE_TMP);
+
+	/*
+	 * Try to merge existing ~/.Xdefaults (if present) with our changes. If there is existing
+	 * key/values, they will be replaced with our. If XrmCombineFileDatabase() fails, this means
+	 * there is no ~/.Xdefaults, so we don't need to backup it; opposite, backup it before we do
+	 * final rename.
+	 */
+	status = XrmCombineFileDatabase(db_file.c_str(), &db, 0);
+	XrmPutFileDatabase(db, tmp_db_file.c_str());
+	//XrmSetDatabase(fl_display, db);
+	XrmDestroyDatabase(db);
+	if(status) {
+		edelib::String db_backup = edelib::build_filename("/", home.c_str(), USER_XRESOURCE_SAVED);
+		edelib::file_rename(db_file.c_str(), db_backup.c_str());
+	} 
+
+	edelib::file_rename(tmp_db_file.c_str(), db_file.c_str());
+}
+
+void Xsm::xresource_undo(void) {
+	edelib::String home, db_file_backup, db_file;
+
+	home = edelib::dir_home();
+	db_file_backup = edelib::build_filename("/", home.c_str(), USER_XRESOURCE_SAVED);
+	db_file = edelib::build_filename("/", home.c_str(), USER_XRESOURCE);
+
+	/*
+	 * If we have backup, restore it; otherwise delete ~/.Xdefaults.
+	 * TODO: what if user something write in it? Changes will be lost...
+	 */
+	if(edelib::file_exists(db_file_backup.c_str()))
+		edelib::file_rename(db_file_backup.c_str(), db_file.c_str());
+	else
+		edelib::file_remove(db_file.c_str());
+}
+
 bool Xsm::load_serialized(const char* file) {
 	TiXmlDocument doc(file);
 	if(!doc.LoadFile())
@@ -96,6 +249,7 @@ bool Xsm::load_serialized(const char* file) {
 		}
 	}
 
+	xresource_replace();
 	return true;
 }
 
@@ -169,5 +323,7 @@ bool Xsm::save_serialized(const char* file) {
 	setting_file.close();
 	edelib::xsettings_list_free(settings);
 
+	xresource_undo();
+
 	return true;
 }

evoke/Xsm.h

@@ -17,6 +17,7 @@
 
 /*
  * XSETTINGS manager with serialization capability.
+ * Also it will write/undo to xrdb (X Resource database).
  */
 class Xsm : public edelib::XSettingsManager {
 	public:
@@ -24,6 +25,11 @@ class Xsm : public edelib::XSettingsManager {
 		~Xsm();
 		bool load_serialized(const char* file);
 		bool save_serialized(const char* file);
+
+		// replace XResource values from one from XSETTINGS
+		void xresource_replace(void);
+		// undo old XResource values
+		void xresource_undo(void);
 };
 
 #endif