Formspec: Introduce default element styling/theming

This introduces a new setting to customize the default appearance
of formspecs. Server-sent 'formspec prepends' will internally
overwrite this setting.

doc/lua_api.md

@@ -3632,9 +3632,9 @@ Some types may inherit styles from parent types.
     * bgimg - standard background image. Defaults to none.
     * bgimg_hovered - background image when hovered. Defaults to bgimg when not provided.
         * This is deprecated, use states instead.
-    * bgimg_middle - Makes the bgimg textures render in 9-sliced mode and defines the middle rect.
+    * bgimg_middle - Replaces the default border. Defines the middle rect for 9-sliced mode.
                      See background9[] documentation for more details. This property also pads the
-                     button's content when set.
+                     button's content when set. When `border` is set to false
     * bgimg_pressed - background image when pressed. Defaults to bgimg when not provided.
         * This is deprecated, use states instead.
     * font - Sets font type. This is a comma separated list of options. Valid options:

doc/texture_packs.md

@@ -38,6 +38,10 @@ A key-value config file with the following keys:
 * `textdomain`: Textdomain used to translate title and description.
   Defaults to the texture pack name.
   See [Translating content meta](lua_api.md#translating-content-meta).
+* `formspec_theme`: optional. Default formspec styling.
+  This is a newline separated list of `style_type[...]` values.
+* `formspec_version_theme`: optional. Indicates the minimal [formspec version](lua_api.md)
+  needed to properly display `formspec_theme`. On older clients, this suppresses warnings.
 
 ### `description.txt`
 **Deprecated**, you should use texture_pack.conf instead.

games/devtest/mods/testformspec/formspec.lua

@@ -235,7 +235,7 @@ local style_fs = [[
 	style[one_btn15;border=false;bgcolor=#1cc;bgimg=testformspec_bg.png;bgimg_hovered=testformspec_bg_hovered.png;bgimg_pressed=testformspec_bg_pressed.png]
 	item_image_button[1.25,9.6;1,1;testformspec:item;one_btn15;Bg]
 
-	style[one_btn16;border=false;bgimg=testformspec_bg_9slice.png;bgimg_middle=4,6;padding=5,7;fgimg=testformspec_bg.png;fgimg_middle=1]
+	style[one_btn16;bgimg=testformspec_bg_9slice.png;bgimg_middle=4,6;padding=5,7;fgimg=testformspec_bg.png;fgimg_middle=1]
 	style[one_btn16:hovered;bgimg=testformspec_bg_9slice_hovered.png;fgimg=testformspec_bg_hovered.png]
 	style[one_btn16:pressed;bgimg=testformspec_bg_9slice_pressed.png;fgimg=testformspec_bg_pressed.png]
 	style[one_btn16:focused;bgimg=testformspec_bg_9slice_focused.png;fgimg=testformspec_bg_focused.png]

src/gui/StyleSpec.h

@@ -380,12 +380,24 @@ public:
 
 	StyleSpec &operator|=(const StyleSpec &other)
 	{
+		u32 props_set = 0;
+		static_assert(sizeof(props_set) * 8 > NUM_PROPERTIES);
+
 		for (size_t i = 0; i < NUM_PROPERTIES; i++) {
 			auto prop = (Property)i;
 			if (other.hasProperty(prop)) {
+				props_set |= (1 << i);
 				set(prop, other.get(prop, ""));
 			}
 		}
+		if ((props_set & (1 << FGIMG | 1 << FGIMG_MIDDLE)) == (1 << FGIMG)) {
+			// Image was specified without 9-slice. Reset to non-9-slice.
+			set(FGIMG_MIDDLE, "");
+		}
+		if ((props_set & (1 << BGIMG | 1 << BGIMG_MIDDLE)) == (1 << BGIMG)) {
+			// Image was specified without 9-slice. Reset to non-9-slice.
+			set(BGIMG_MIDDLE, "");
+		}
 
 		return *this;
 	}

src/gui/guiButton.cpp

@@ -255,9 +255,10 @@ void GUIButton::draw()
 
 	video::IVideoDriver* driver = Environment->getVideoDriver();
 	IGUISkin *skin = Environment->getSkin();
+	const bool is_9_slice_border = BgMiddle.getArea() > 0;
 	// END PATCH
 
-	if (DrawBorder)
+	if (DrawBorder && !is_9_slice_border)
 	{
 		if (!Pressed)
 		{
@@ -303,13 +304,17 @@ void GUIButton::draw()
 
 		// PATCH
 		video::ITexture* texture = ButtonImages[(u32)imageState].Texture;
+		// FIXME: Vertices can only be darkened because [0, 255] is normalized to [0, 1]
+		// For reference: irr/src/OpenGL/Driver.cpp -> `vt2DImage`
 		video::SColor image_colors[] = { BgColor, BgColor, BgColor, BgColor };
-		if (BgMiddle.getArea() == 0) {
+		if (!is_9_slice_border) {
+			// Regular image button
 			driver->draw2DImage(texture,
 					ScaleImage? AbsoluteRect : core::rect<s32>(pos, sourceRect.getSize()),
 					sourceRect, &AbsoluteClippingRect,
 					image_colors, UseAlphaChannel);
-		} else {
+		} else if (DrawBorder) {
+			// The background image is 9-slice --> use as new border style
 			draw2DImage9Slice(driver, texture,
 					ScaleImage ? AbsoluteRect : core::rect<s32>(pos, sourceRect.getSize()),
 					sourceRect, BgMiddle, &AbsoluteClippingRect, image_colors);

src/gui/guiButtonImage.cpp

@@ -26,16 +26,9 @@ GUIButtonImage::GUIButtonImage(gui::IGUIEnvironment *environment,
 
 void GUIButtonImage::draw()
 {
-	if (isDrawingBorder()) {
-		// `GUIButton` also allows drawing different textures depending on
-		// `EGUI_BUTTON_STATE` --> Skip everything if the border is disabled (else case).
 	GUIButton::draw();
-	} else {
-		IGUIElement::draw();
-	}
 }
 
-
 void GUIButtonImage::setForegroundImage(irr_ptr<video::ITexture> image,
 		const core::rect<s32> &middle)
 {

src/gui/guiEngine.cpp

@@ -8,6 +8,7 @@
 #include "client/guiscalingfilter.h"
 #include "client/renderingengine.h"
 #include "client/shader.h"
+#include "client/texturepaths.h"
 #include "client/tile.h"
 #include "clientdynamicinfo.h"
 #include "config.h"
@@ -41,14 +42,18 @@ void TextDestGuiEngine::gotText(const StringMap &fields)
 }
 
 /******************************************************************************/
+MenuTextureSource::MenuTextureSource(video::IVideoDriver* driver) :
+	m_driver(driver)
+{
+	g_settings->registerChangedCallback("texture_path", onTxpSettingChanged, this);
+}
+
 MenuTextureSource::~MenuTextureSource()
 {
-	u32 before = m_driver->getTextureCount();
+	g_settings->deregisterAllChangedCallbacks(this);
 
-	for (const auto &it: m_to_delete) {
+	u32 before = m_driver->getTextureCount();
-		m_driver->removeTexture(it);
+	cleanupTextures();
-	}
-	m_to_delete.clear();
 
 	infostream << "~MenuTextureSource() before cleanup: "<< before
 			<< " after: " << m_driver->getTextureCount() << std::endl;
@@ -68,8 +73,14 @@ video::ITexture *MenuTextureSource::getTexture(const std::string &name, u32 *id)
 	if (retval)
 		return retval;
 
-	verbosestream << "MenuTextureSource: loading " << name << std::endl;
+	// Try to find the texture in the active texture pack
-	video::IImage *image = m_driver->createImageFromFile(name.c_str());
+	std::string path;
+	if (!fs::IsPathAbsolute(name))
+		path = getTexturePath(name, nullptr);
+
+	const char *filepath = path.empty() ? name.c_str() : path.c_str();
+	verbosestream << "MenuTextureSource: loading " << filepath << std::endl;
+	video::IImage *image = m_driver->createImageFromFile(filepath);
 	if (!image)
 		return NULL;
 
@@ -81,6 +92,20 @@ video::ITexture *MenuTextureSource::getTexture(const std::string &name, u32 *id)
 	return retval;
 }
 
+void MenuTextureSource::cleanupTextures()
+{
+	for (const auto &it: m_to_delete) {
+		m_driver->removeTexture(it);
+	}
+	m_to_delete.clear();
+}
+
+void MenuTextureSource::onTxpSettingChanged(const std::string &name, void *data)
+{
+	((MenuTextureSource *)data)->cleanupTextures();
+	clearTextureNameCache();
+}
+
 /******************************************************************************/
 /** MenuMusicFetcher                                                          */
 /******************************************************************************/

src/gui/guiEngine.h

@@ -74,7 +74,7 @@ public:
 	 * default constructor
 	 * @param driver the video driver to load textures from
 	 */
-	MenuTextureSource(video::IVideoDriver *driver) : m_driver(driver) {};
+	MenuTextureSource(video::IVideoDriver *driver);
 
 	/**
 	 * destructor, removes all loaded textures
@@ -89,6 +89,12 @@ public:
 	video::ITexture *getTexture(const std::string &name, u32 *id = NULL);
 
 private:
+	/** Unloads all textures in `m_to_delete` */
+	void cleanupTextures();
+
+	/** Update the texture cache */
+	static void onTxpSettingChanged(const std::string &name, void *data);
+
 	/** driver to get textures from */
 	video::IVideoDriver *m_driver = nullptr;
 	/** set of textures to delete */

src/gui/guiFormSpecMenu.cpp

@@ -114,10 +114,15 @@ GUIFormSpecMenu::GUIFormSpecMenu(JoystickController *joystick,
 
 	m_tooltip_show_delay = (u32)g_settings->getS32("tooltip_show_delay");
 	m_tooltip_append_itemname = g_settings->getBool("tooltip_append_itemname");
+
+	g_settings->registerChangedCallback("texture_path", onTxpSettingChanged, this);
+	setThemeFromSettings();
 }
 
 GUIFormSpecMenu::~GUIFormSpecMenu()
 {
+	g_settings->deregisterAllChangedCallbacks(this);
+
 	removeAll();
 
 	delete m_selected_item;
@@ -2618,15 +2623,9 @@ void GUIFormSpecMenu::parsePadding(parserData *data, const std::string &element)
 			<< "'" << std::endl;
 }
 
-void GUIFormSpecMenu::parseStyle(parserData *data, const std::string &element)
+void GUIFormSpecMenu::parse_style_to_map(StyleSpecMap &out, const std::string &element,
+		std::unordered_set<std::string> *prop_warned)
 {
-	if (data->type != "style" && data->type != "style_type") {
-		errorstream << "Invalid style element type: '" << data->type << "'" << std::endl;
-		return;
-	}
-
-	bool style_type = (data->type == "style_type");
-
 	std::vector<std::string> parts = split(element, ';');
 
 	if (parts.size() < 2) {
@@ -2653,11 +2652,11 @@ void GUIFormSpecMenu::parseStyle(parserData *data, const std::string &element)
 
 		StyleSpec::Property prop = StyleSpec::GetPropertyByName(propname);
 		if (prop == StyleSpec::NONE) {
-			if (property_warned.find(propname) != property_warned.end()) {
+			if (prop_warned && prop_warned->find(propname) != prop_warned->end()) {
 				warningstream << "Invalid style element (Unknown property " << propname << "): '"
 						<< element
 						<< "'" << std::endl;
-				property_warned.insert(propname);
+				prop_warned->insert(propname);
 			}
 			continue;
 		}
@@ -2705,11 +2704,7 @@ void GUIFormSpecMenu::parseStyle(parserData *data, const std::string &element)
 			continue;
 		}
 
-		if (style_type) {
+		out[selector].push_back(selector_spec);
-			theme_by_type[selector].push_back(selector_spec);
-		} else {
-			theme_by_name[selector].push_back(selector_spec);
-		}
 
 		// Backwards-compatibility for existing _hovered/_pressed properties
 		if (selector_spec.hasProperty(StyleSpec::BGCOLOR_HOVERED)
@@ -2728,11 +2723,7 @@ void GUIFormSpecMenu::parseStyle(parserData *data, const std::string &element)
 				hover_spec.set(StyleSpec::FGIMG, selector_spec.get(StyleSpec::FGIMG_HOVERED, ""));
 			}
 
-			if (style_type) {
+			out[selector].push_back(hover_spec);
-				theme_by_type[selector].push_back(hover_spec);
-			} else {
-				theme_by_name[selector].push_back(hover_spec);
-			}
 		}
 		if (selector_spec.hasProperty(StyleSpec::BGCOLOR_PRESSED)
 				|| selector_spec.hasProperty(StyleSpec::BGIMG_PRESSED)
@@ -2750,15 +2741,22 @@ void GUIFormSpecMenu::parseStyle(parserData *data, const std::string &element)
 				press_spec.set(StyleSpec::FGIMG, selector_spec.get(StyleSpec::FGIMG_PRESSED, ""));
 			}
 
-			if (style_type) {
+			out[selector].push_back(press_spec);
-				theme_by_type[selector].push_back(press_spec);
-			} else {
-				theme_by_name[selector].push_back(press_spec);
 		}
 	}
+}
+
+void GUIFormSpecMenu::parseStyle(parserData *data, const std::string &element)
+{
+	if (data->type != "style" && data->type != "style_type") {
+		errorstream << "Invalid style element type: '" << data->type << "'" << std::endl;
+		return;
 	}
 
-	return;
+	bool style_type = (data->type == "style_type");
+
+	parse_style_to_map(style_type ? theme_by_type : theme_by_name,
+		element, &property_warned);
 }
 
 void GUIFormSpecMenu::parseSetFocus(parserData*, const std::string &element)
@@ -3041,7 +3039,7 @@ void GUIFormSpecMenu::regenerateGui(v2u32 screensize)
 	m_dropdowns.clear();
 	m_scroll_containers.clear();
 	theme_by_name.clear();
-	theme_by_type.clear();
+	theme_by_type = theme_by_type_default;
 	m_clickthrough_elements.clear();
 	field_enter_after_edit.clear();
 	field_close_on_enter.clear();
@@ -5028,6 +5026,40 @@ std::wstring GUIFormSpecMenu::getLabelByID(s32 id)
 	return L"";
 }
 
+
+void GUIFormSpecMenu::setThemeFromSettings()
+{
+	theme_by_type_default.clear();
+
+	const std::string settingspath = g_settings->get("texture_path") + DIR_DELIM + "texture_pack.conf";
+	Settings settings;
+	if (!settings.readConfigFile(settingspath.c_str()))
+		return;
+	if (!settings.exists("formspec_theme"))
+		return;
+
+	std::unordered_set<std::string> *prop_warned = nullptr;
+	{
+		u16 fs_ver = FORMSPEC_API_VERSION;
+		settings.getU16NoEx("formspec_version_theme", fs_ver);
+		if (fs_ver <= FORMSPEC_API_VERSION)
+			prop_warned = &property_warned;
+		// else: silence
+	}
+
+	auto splits = split(settings.get("formspec_theme"), '\n');
+	for (const std::string &s : splits) {
+		parse_style_to_map(theme_by_type_default, s, prop_warned);
+	}
+}
+
+void GUIFormSpecMenu::onTxpSettingChanged(const std::string &name, void *data)
+{
+	GUIFormSpecMenu *me = (GUIFormSpecMenu *)data;
+	me->setThemeFromSettings();
+	me->regenerateGui(me->m_screensize_old);
+}
+
 StyleSpec GUIFormSpecMenu::getDefaultStyleForElement(const std::string &type,
 		const std::string &name, const std::string &parent_type) {
 	return getStyleForElement(type, name, parent_type)[StyleSpec::STATE_DEFAULT];

src/gui/guiFormSpecMenu.h

@@ -302,10 +302,14 @@ protected:
 	bool precheckElement(const std::string &name, const std::string &element,
 		size_t args_min, size_t args_max, std::vector<std::string> &parts);
 
-	std::unordered_map<std::string, std::vector<StyleSpec>> theme_by_type;
+	using StyleSpecMap = std::unordered_map<std::string, std::vector<StyleSpec>>;
-	std::unordered_map<std::string, std::vector<StyleSpec>> theme_by_name;
+	StyleSpecMap theme_by_type, theme_by_name,
+		theme_by_type_default;
 	std::unordered_set<std::string> property_warned;
 
+	void setThemeFromSettings();
+	static void onTxpSettingChanged(const std::string &name, void *data);
+
 	StyleSpec getDefaultStyleForElement(const std::string &type,
 			const std::string &name="", const std::string &parent_type="");
 	std::array<StyleSpec, StyleSpec::NUM_STATES> getStyleForElement(const std::string &type,
@@ -483,6 +487,8 @@ private:
 	void parseAnchor(parserData *data, const std::string &element);
 	bool parsePaddingDirect(parserData *data, const std::string &element);
 	void parsePadding(parserData *data, const std::string &element);
+	static void parse_style_to_map(StyleSpecMap &out, const std::string &element,
+		std::unordered_set<std::string> *prop_warned);
 	void parseStyle(parserData *data, const std::string &element);
 	void parseSetFocus(parserData *, const std::string &element);
 	void parseModel(parserData *data, const std::string &element);