theme.cpp

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/*
    Copyright (C) 2003 - 2025
    by David White <dave@whitevine.net>
    Part of the Battle for Wesnoth Project https://www.wesnoth.org/
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY.
 
    See the COPYING file for more details.
*/
 
#include "theme.hpp"
 
#include "desktop/battery_info.hpp"
#include "gettext.hpp"
#include "hotkey/hotkey_command.hpp"
#include "hotkey/hotkey_item.hpp"
#include "log.hpp"
#include "sdl/rect.hpp"
#include "serialization/string_utils.hpp"
#include "wml_exception.hpp"
#include "game_config_view.hpp"
#include <sstream>
#include <utility>
 
static lg::log_domain log_display("display");
#define DBG_DP LOG_STREAM(debug, log_display)
#define LOG_DP LOG_STREAM(info, log_display)
#define ERR_DP LOG_STREAM(err, log_display)
 
namespace
{
 
const std::size_t DefaultFontSize = font::SIZE_NORMAL;
const color_t DefaultFontRGB {200, 200, 200};
 
_rect ref_rect {0, 0, 0, 0};
}
 
static std::size_t compute(std::string expr, std::size_t ref1, std::size_t ref2 = 0)
{
    std::size_t ref = 0;
    if(expr[0] == '=') {
        ref = ref1;
        expr = expr.substr(1);
    } else if((expr[0] == '+') || (expr[0] == '-')) {
        ref = ref2;
    }
 
    return ref + atoi(expr.c_str());
}
 
// If x2 or y2 are not specified, use x1 and y1 values
static _rect read_rect(const config& cfg)
{
    _rect rect {0, 0, 0, 0};
    std::vector<std::string> items = utils::split(cfg["rect"].str());
    if(items.size() >= 1)
        rect.x1 = atoi(items[0].c_str());
 
    if(items.size() >= 2)
        rect.y1 = atoi(items[1].c_str());
 
    if(items.size() >= 3)
        rect.x2 = atoi(items[2].c_str());
    else
        rect.x2 = rect.x1;
 
    if(items.size() >= 4)
        rect.y2 = atoi(items[3].c_str());
    else
        rect.y2 = rect.y1;
 
    return rect;
}
 
static SDL_Rect read_sdl_rect(const config& cfg)
{
    SDL_Rect sdlrect;
    const _rect rect = read_rect(cfg);
    sdlrect.x = rect.x1;
    sdlrect.y = rect.y1;
    sdlrect.w = (rect.x2 > rect.x1) ? (rect.x2 - rect.x1) : 0;
    sdlrect.h = (rect.y2 > rect.y1) ? (rect.y2 - rect.y1) : 0;
 
    return sdlrect;
}
 
static std::string resolve_rect(const std::string& rect_str)
{
    _rect rect {0, 0, 0, 0};
    std::stringstream resolved;
    const std::vector<std::string> items = utils::split(rect_str.c_str());
    if(items.size() >= 1) {
        rect.x1 = compute(items[0], ref_rect.x1, ref_rect.x2);
        resolved << rect.x1;
    }
    if(items.size() >= 2) {
        rect.y1 = compute(items[1], ref_rect.y1, ref_rect.y2);
        resolved << "," << rect.y1;
    }
    if(items.size() >= 3) {
        rect.x2 = compute(items[2], ref_rect.x2, rect.x1);
        resolved << "," << rect.x2;
    }
    if(items.size() >= 4) {
        rect.y2 = compute(items[3], ref_rect.y2, rect.y1);
        resolved << "," << rect.y2;
    }
 
    // DBG_DP << "Rect " << rect_str << "\t: " << resolved.str();
 
    ref_rect = rect;
    return resolved.str();
}
 
static config& find_ref(const std::string& id, config& cfg, bool remove = false)
{
    static config empty_config;
 
    config::all_children_itors itors = cfg.all_children_range();
    for(config::all_children_iterator i = itors.begin(); i != itors.end(); ++i) {
        config& icfg = i->cfg;
        if(i->cfg["id"] == id) {
            if(remove) {
                cfg.erase(i);
                return empty_config;
            } else {
                return icfg;
            }
        }
 
        // Recursively look in children.
        config& c = find_ref(id, icfg, remove);
        if(&c != &empty_config) {
            return c;
        }
    }
 
    // Not found.
    return empty_config;
}
 
#ifdef DEBUG
 
// to be called from gdb
static config& find_ref(const char* id, config& cfg)
{
    return find_ref(std::string(id), cfg);
}
 
namespace
{
// avoid some compiler warnings in stricter mode.
static config cfg;
static config& result = find_ref("", cfg);
} // namespace
 
#endif
 
/**
 * Returns a copy of the wanted resolution.
 *
 * The function returns a copy since our caller uses a copy of this resolution
 * as base to expand a partial resolution.
 *
 * @param resolutions             A config object containing the expanded
 *                                resolutions.
 * @param id                      The id of the resolution to return.
 *
 * @throw config::error           If the @p id is not found.
 *
 * @returns                       A copy of the resolution config.
 */
static config get_resolution(const config& resolutions, const std::string& id)
{
    for(const auto& resolution : resolutions.child_range("resolution")) {
        if(resolution["id"] == id) {
            return resolution;
        }
    }
 
    throw config::error("[partialresolution] refers to non-existent [resolution] " + id);
}
 
/**
 * Returns a config with all partial resolutions of a theme expanded.
 *
 * @param theme                   The original object, whose objects need to be
 *                                expanded.
 *
 * @returns                       A new object with the expanded resolutions in
 *                                a theme. This object no longer contains
 *                                partial resolutions.
 */
static config expand_partialresolution(const config& theme)
{
    config result;
 
    // Add all the resolutions
    for(const auto& resolution : theme.child_range("resolution")) {
        result.add_child("resolution", resolution);
    }
 
    // Resolve all the partialresolutions
    for(const auto& part : theme.child_range("partialresolution")) {
        config resolution = get_resolution(result, part["inherits"]);
        resolution.merge_attributes(part);
 
        for(const auto& remove : part.child_range("remove")) {
            VALIDATE(!remove["id"].empty(), missing_mandatory_wml_key("[theme][partialresolution][remove]", "id"));
 
            find_ref(remove["id"], resolution, true);
        }
 
        for(const auto& change : part.child_range("change")) {
            VALIDATE(!change["id"].empty(), missing_mandatory_wml_key("[theme][partialresolution][change]", "id"));
 
            config& target = find_ref(change["id"], resolution, false);
            target.merge_attributes(change);
        }
 
        // cannot add [status] sub-elements, but who cares
        for(const auto& add : part.child_range("add")) {
            for(const auto [key, cfg] : add.all_children_view()) {
                resolution.add_child(key, cfg);
            }
        }
 
        result.add_child("resolution", resolution);
    }
 
    return result;
}
 
static void do_resolve_rects(const config& cfg, config& resolved_config, config* resol_cfg = nullptr)
{
    // recursively resolve children
    for(const auto [child_key, child_cfg] : cfg.all_children_view()) {
        config& dest = resolved_config.add_child(child_key);
        do_resolve_rects(child_cfg, dest, child_key == "resolution" ? &dest : resol_cfg);
    }
 
    // copy all key/values
    resolved_config.merge_attributes(cfg);
 
    // override default reference rect with "ref" parameter if any
    if(!cfg["ref"].empty()) {
        if(resol_cfg == nullptr) {
            ERR_DP << "Use of ref= outside a [resolution] block";
        } else {
            // DBG_DP << ">> Looking for " << cfg["ref"];
            const config& ref = find_ref(cfg["ref"], *resol_cfg);
 
            if(ref["id"].empty()) {
                ERR_DP << "Reference to non-existent rect id \"" << cfg["ref"] << "\"";
            } else if(ref["rect"].empty()) {
                ERR_DP << "Reference to id \"" << cfg["ref"] << "\" which does not have a \"rect\"";
            } else {
                ref_rect = read_rect(ref);
            }
        }
    }
    // resolve the rect value to absolute coordinates
    if(!cfg["rect"].empty()) {
        resolved_config["rect"] = resolve_rect(cfg["rect"]);
    }
}
 
theme::object::object()
    : location_modified_(false)
    , id_()
    , loc_(sdl::empty_rect)
    , relative_loc_(sdl::empty_rect)
    , last_screen_(sdl::empty_rect)
    , xanchor_(object::FIXED)
    , yanchor_(object::FIXED)
    , spec_width_(0)
    , spec_height_(0)
{
}
 
theme::object::object(std::size_t sw, std::size_t sh, const config& cfg)
    : location_modified_(false)
    , id_(cfg["id"])
    , loc_(read_sdl_rect(cfg))
    , relative_loc_(sdl::empty_rect)
    , last_screen_(sdl::empty_rect)
    , xanchor_(read_anchor(cfg["xanchor"]))
    , yanchor_(read_anchor(cfg["yanchor"]))
    , spec_width_(sw)
    , spec_height_(sh)
{
}
 
theme::border_t::border_t()
    : size(0.0)
    , background_image()
    , tile_image()
    , show_border(true)
{
}
 
theme::border_t::border_t(const config& cfg)
    : size(cfg["border_size"].to_double())
    , background_image(cfg["background_image"])
    , tile_image(cfg["tile_image"])
    , show_border(cfg["show_border"].to_bool(true))
{
    VALIDATE(size >= 0.0 && size <= 0.5, _("border_size should be between 0.0 and 0.5."));
}
 
rect& theme::object::location(const SDL_Rect& screen) const
{
    if(last_screen_ == screen && !location_modified_)
        return relative_loc_;
 
    last_screen_ = screen;
 
    switch(xanchor_) {
        case FIXED:
            relative_loc_.x = loc_.x;
            relative_loc_.w = loc_.w;
            break;
        case TOP_ANCHORED:
            relative_loc_.x = loc_.x;
            relative_loc_.w = loc_.w + screen.w - std::min<std::size_t>(spec_width_, loc_.w + screen.w);
            break;
        case BOTTOM_ANCHORED:
            relative_loc_.x = loc_.x + screen.w - std::min<std::size_t>(spec_width_, loc_.x + screen.w);
            relative_loc_.w = loc_.w;
            break;
        case PROPORTIONAL:
            relative_loc_.x = (loc_.x * screen.w) / spec_width_;
            relative_loc_.w = (loc_.w * screen.w) / spec_width_;
            break;
        default:
            assert(false);
    }
 
    switch(yanchor_) {
        case FIXED:
            relative_loc_.y = loc_.y;
            relative_loc_.h = loc_.h;
            break;
        case TOP_ANCHORED:
            relative_loc_.y = loc_.y;
            relative_loc_.h = loc_.h + screen.h - std::min<std::size_t>(spec_height_, loc_.h + screen.h);
            break;
        case BOTTOM_ANCHORED:
            relative_loc_.y = loc_.y + screen.h - std::min<std::size_t>(spec_height_, loc_.y + screen.h);
            relative_loc_.h = loc_.h;
            break;
        case PROPORTIONAL:
            relative_loc_.y = (loc_.y * screen.h) / spec_height_;
            relative_loc_.h = (loc_.h * screen.h) / spec_height_;
            break;
        default:
            assert(false);
    }
 
    relative_loc_.w = std::min<int>(relative_loc_.w, screen.w);
    if(relative_loc_.x > screen.w) {
        relative_loc_.x = std::min<int>(relative_loc_.x, screen.w - relative_loc_.w);
    }
    relative_loc_.w = std::min<int>(relative_loc_.w, screen.w - relative_loc_.x);
 
    relative_loc_.h = std::min<int>(relative_loc_.h, screen.h);
    if(relative_loc_.y > screen.h) {
        relative_loc_.y = std::min<int>(relative_loc_.y, screen.h - relative_loc_.h);
    }
    relative_loc_.h = std::min<int>(relative_loc_.h, screen.h - relative_loc_.y);
 
    return relative_loc_;
}
 
theme::object::ANCHORING theme::object::read_anchor(const std::string& str)
{
    static const std::string top_anchor = "top", left_anchor = "left", bot_anchor = "bottom", right_anchor = "right",
                             proportional_anchor = "proportional";
    if(str == top_anchor || str == left_anchor)
        return TOP_ANCHORED;
    else if(str == bot_anchor || str == right_anchor)
        return BOTTOM_ANCHORED;
    else if(str == proportional_anchor)
        return PROPORTIONAL;
    else
        return FIXED;
}
 
void theme::object::modify_location(const _rect& rect)
{
    loc_.x = rect.x1;
    loc_.y = rect.y1;
    loc_.w = rect.x2 - rect.x1;
    loc_.h = rect.y2 - rect.y1;
    location_modified_ = true;
}
 
void theme::object::modify_location(const std::string& rect_str, SDL_Rect location_ref_rect)
{
    _rect rect {0, 0, 0, 0};
    const std::vector<std::string> items = utils::split(rect_str.c_str());
    if(items.size() >= 1) {
        rect.x1 = compute(items[0], location_ref_rect.x, location_ref_rect.x + location_ref_rect.w);
    }
    if(items.size() >= 2) {
        rect.y1 = compute(items[1], location_ref_rect.y, location_ref_rect.y + location_ref_rect.h);
    }
    if(items.size() >= 3) {
        rect.x2 = compute(items[2], location_ref_rect.x + location_ref_rect.w, rect.x1);
    }
    if(items.size() >= 4) {
        rect.y2 = compute(items[3], location_ref_rect.y + location_ref_rect.h, rect.y1);
    }
    modify_location(rect);
}
 
theme::label::label()
    : text_()
    , icon_()
    , font_()
    , font_rgb_set_(false)
    , font_rgb_(DefaultFontRGB)
{
}
 
theme::label::label(std::size_t sw, std::size_t sh, const config& cfg)
    : object(sw, sh, cfg)
    , text_(cfg["prefix"].str() + cfg["prefix_literal"].str() + cfg["text"].str() + cfg["postfix_literal"].str() + cfg["postfix"].str())
    , icon_(cfg["icon"])
    , font_(cfg["font_size"].to_size_t())
    , font_rgb_set_(false)
    , font_rgb_(DefaultFontRGB)
{
    if(font_ == 0)
        font_ = DefaultFontSize;
 
    if(cfg.has_attribute("font_rgb")) {
        font_rgb_ = color_t::from_rgb_string(cfg["font_rgb"].str());
        font_rgb_set_ = true;
    }
}
 
theme::status_item::status_item(std::size_t sw, std::size_t sh, const config& cfg)
    : object(sw, sh, cfg)
    , prefix_(cfg["prefix"].str() + cfg["prefix_literal"].str())
    , postfix_(cfg["postfix_literal"].str() + cfg["postfix"].str())
    , label_()
    , font_(cfg["font_size"].to_size_t())
    , font_rgb_set_(false)
    , font_rgb_(DefaultFontRGB)
{
    if(font_ == 0)
        font_ = DefaultFontSize;
 
    if(auto label_child = cfg.optional_child("label")) {
        label_ = label(sw, sh, *label_child);
    }
 
    if(cfg.has_attribute("font_rgb")) {
        font_rgb_ = color_t::from_rgb_string(cfg["font_rgb"].str());
        font_rgb_set_ = true;
    }
}
 
theme::panel::panel(std::size_t sw, std::size_t sh, const config& cfg)
    : object(sw, sh, cfg)
    , image_(cfg["image"])
{
}
 
theme::slider::slider()
    : object()
    , title_()
    , tooltip_()
    , image_()
    , overlay_()
    , black_line_(false)
{
}
theme::slider::slider(std::size_t sw, std::size_t sh, const config& cfg)
    : object(sw, sh, cfg)
    , title_(cfg["title"].str() + cfg["title_literal"].str())
    , tooltip_(cfg["tooltip"])
    , image_(cfg["image"])
    , overlay_(cfg["overlay"])
    , black_line_(cfg["black_line"].to_bool(false))
{
}
 
theme::menu::menu()
    : object()
    , button_(true)
    , context_(false)
    , title_()
    , tooltip_()
    , image_()
    , overlay_()
    , items_()
{
}
 
theme::menu::menu(std::size_t sw, std::size_t sh, const config& cfg)
    : object(sw, sh, cfg)
    , button_(cfg["button"].to_bool(true))
    , context_(cfg["is_context_menu"].to_bool(false))
    , title_(cfg["title"].str() + cfg["title_literal"].str())
    , tooltip_(cfg["tooltip"])
    , image_(cfg["image"])
    , overlay_(cfg["overlay"])
    , items_()
{
    for(const auto& item : utils::split(cfg["items"])) {
        items_.emplace_back("id", item);
    }
 
    const auto& cmd = hotkey::get_hotkey_command(items_[0]["id"]);
    if(cfg["auto_tooltip"].to_bool() && tooltip_.empty() && items_.size() == 1) {
        tooltip_ = cmd.description + hotkey::get_names(items_[0]["id"]) + "\n" + cmd.tooltip;
    } else if(cfg["tooltip_name_prepend"].to_bool() && items_.size() == 1) {
        tooltip_ = cmd.description + hotkey::get_names(items_[0]["id"]) + "\n" + tooltip_;
    }
}
 
theme::action::action()
    : object()
    , context_(false)
    , auto_tooltip_(false)
    , tooltip_name_prepend_(false)
    , title_()
    , tooltip_()
    , image_()
    , overlay_()
    , type_()
    , items_()
{
}
 
theme::action::action(std::size_t sw, std::size_t sh, const config& cfg)
    : object(sw, sh, cfg)
    , context_(cfg["is_context_menu"].to_bool())
    , auto_tooltip_(cfg["auto_tooltip"].to_bool(false))
    , tooltip_name_prepend_(cfg["tooltip_name_prepend"].to_bool(false))
    , title_(cfg["title"].str() + cfg["title_literal"].str())
    , tooltip_(cfg["tooltip"])
    , image_(cfg["image"])
    , overlay_(cfg["overlay"])
    , type_(cfg["type"])
    , items_(utils::split(cfg["items"]))
{
}
 
const std::string theme::action::tooltip(std::size_t index) const
{
    const auto& cmd = hotkey::get_hotkey_command(items_[index]);
    std::stringstream result;
    if(auto_tooltip_ && tooltip_.empty() && items_.size() > index) {
        result << cmd.description;
        if(!hotkey::get_names(items_[index]).empty())
            result << "\n" << _("Hotkey(s): ") << hotkey::get_names(items_[index]);
        result << "\n" << cmd.tooltip;
    } else if(tooltip_name_prepend_ && items_.size() == 1) {
        result << cmd.description;
        if(!hotkey::get_names(items_[index]).empty())
            result << "\n" << _("Hotkey(s): ") << hotkey::get_names(items_[index]);
        result << "\n" << tooltip_;
    } else {
        result << tooltip_;
    }
 
    return result.str();
}
 
theme::theme(const config& cfg, const SDL_Rect& screen)
    : theme_reset_event_("theme_reset")
    , cur_theme()
    , cfg_()
    , panels_()
    , labels_()
    , menus_()
    , actions_()
    , context_()
    , status_()
    , main_map_()
    , mini_map_()
    , unit_image_()
    , palette_()
    , border_()
    , screen_dimensions_(screen)
    , cur_spec_width_(0)
    , cur_spec_height_(0)
{
    do_resolve_rects(expand_partialresolution(cfg), cfg_);
    set_resolution(screen);
}
 
bool theme::set_resolution(const SDL_Rect& screen)
{
    screen_dimensions_ = screen;
 
    bool result = false;
 
    int current_rating = 1000000;
    const config* current = nullptr;
    for(const config& i : cfg_.child_range("resolution")) {
        int width = i["width"].to_int();
        int height = i["height"].to_int();
        LOG_DP << "comparing resolution " << screen.w << "," << screen.h << " to " << width << "," << height;
        if(screen.w >= width && screen.h >= height) {
            LOG_DP << "loading theme: " << width << "," << height;
            current = &i;
            result = true;
            break;
        }
 
        const int rating = width * height;
        if(rating < current_rating) {
            current = &i;
            current_rating = rating;
        }
    }
 
    if(!current) {
        if(cfg_.child_count("resolution")) {
            ERR_DP << "No valid resolution found";
        }
        return false;
    }
    cur_spec_width_ = (*current)["width"].to_size_t();
    cur_spec_height_ = (*current)["height"].to_size_t();
 
    std::map<std::string, std::string> title_stash_menus;
    std::vector<theme::menu>::iterator m;
    for(m = menus_.begin(); m != menus_.end(); ++m) {
        if(!m->title().empty() && !m->get_id().empty())
            title_stash_menus[m->get_id()] = m->title();
    }
 
    std::map<std::string, std::string> title_stash_actions;
    std::vector<theme::action>::iterator a;
    for(a = actions_.begin(); a != actions_.end(); ++a) {
        if(!a->title().empty() && !a->get_id().empty())
            title_stash_actions[a->get_id()] = a->title();
    }
 
    panels_.clear();
    labels_.clear();
    status_.clear();
    menus_.clear();
    actions_.clear();
    sliders_.clear();
 
    add_object(cur_spec_width_, cur_spec_height_, *current);
 
    for(m = menus_.begin(); m != menus_.end(); ++m) {
        if(title_stash_menus.find(m->get_id()) != title_stash_menus.end())
            m->set_title(title_stash_menus[m->get_id()]);
    }
 
    for(a = actions_.begin(); a != actions_.end(); ++a) {
        if(title_stash_actions.find(a->get_id()) != title_stash_actions.end())
            a->set_title(title_stash_actions[a->get_id()]);
    }
 
    theme_reset_event_.notify_observers();
 
    return result;
}
 
void theme::add_object(std::size_t sw, std::size_t sh, const config& cfg)
{
    if(const auto c = cfg.optional_child("main_map")) {
        main_map_ = object(sw, sh, c.value());
    }
 
    if(const auto c = cfg.optional_child("mini_map")) {
        mini_map_ = object(sw, sh, c.value());
    }
 
    if(const auto c = cfg.optional_child("palette")) {
        palette_ = object(sw, sh, c.value());
    }
 
    if(const auto status_cfg = cfg.optional_child("status")) {
        for(const auto [child_key, child_cfg] : status_cfg->all_children_view()) {
            status_[child_key].reset(new status_item(sw, sh, child_cfg));
        }
        if(const auto unit_image_cfg = status_cfg->optional_child("unit_image")) {
            unit_image_ = object(sw, sh, unit_image_cfg.value());
        } else {
            unit_image_ = object();
        }
    }
 
    for(const config& p : cfg.child_range("panel")) {
        panel new_panel(sw, sh, p);
        set_object_location(new_panel, p["rect"], p["ref"]);
        panels_.push_back(new_panel);
    }
 
    for(const config& lb : cfg.child_range("label")) {
        label new_label(sw, sh, lb);
        set_object_location(new_label, lb["rect"], lb["ref"]);
        labels_.push_back(new_label);
    }
 
    for(const config& m : cfg.child_range("menu")) {
        menu new_menu(sw, sh, m);
        DBG_DP << "adding menu: " << (new_menu.is_context() ? "is context" : "not context");
        if(new_menu.is_context())
            context_ = new_menu;
        else {
            set_object_location(new_menu, m["rect"], m["ref"]);
            menus_.push_back(new_menu);
        }
 
        DBG_DP << "done adding menu...";
    }
 
    for(const config& a : cfg.child_range("action")) {
        action new_action(sw, sh, a);
        DBG_DP << "adding action: " << (new_action.is_context() ? "is context" : "not context");
        if(new_action.is_context())
            action_context_ = new_action;
        else {
            set_object_location(new_action, a["rect"], a["ref"]);
            actions_.push_back(new_action);
        }
 
        DBG_DP << "done adding action...";
    }
 
    for(const config& s : cfg.child_range("slider")) {
        slider new_slider(sw, sh, s);
        DBG_DP << "adding slider";
        set_object_location(new_slider, s["rect"], s["ref"]);
        sliders_.push_back(new_slider);
 
        DBG_DP << "done adding slider...";
    }
 
    if(auto c = cfg.optional_child("main_map_border")) {
        border_ = border_t(*c);
    }
 
    // Battery charge indicator is always hidden if there isn't enough horizontal space
    // (GitHub issue #3714)
    static const int BATTERY_ICON_MIN_WIDTH = 1152;
    if(!desktop::battery_info::does_device_have_battery() || screen_dimensions_.w < BATTERY_ICON_MIN_WIDTH) {
        if(auto c = cfg.optional_child("no_battery")) {
            modify(*c);
        }
    }
}
 
void theme::remove_object(const std::string& id)
{
    if(status_.erase(id) > 0u) {
        return;
    }
 
    for(auto p = panels_.begin(); p != panels_.end(); ++p) {
        if(p->get_id() == id) {
            panels_.erase(p);
            return;
        }
    }
    for(auto l = labels_.begin(); l != labels_.end(); ++l) {
        if(l->get_id() == id) {
            labels_.erase(l);
            return;
        }
    }
    for(auto m = menus_.begin(); m != menus_.end(); ++m) {
        if(m->get_id() == id) {
            menus_.erase(m);
            return;
        }
    }
    for(auto a = actions_.begin(); a != actions_.end(); ++a) {
        if(a->get_id() == id) {
            actions_.erase(a);
            return;
        }
    }
    for(auto s = sliders_.begin(); s != sliders_.end(); ++s) {
        if(s->get_id() == id) {
            sliders_.erase(s);
            return;
        }
    }
 
    std::stringstream stream;
    stream << "theme object " << id << " not found";
    throw config::error(stream.str());
}
 
void theme::set_object_location(theme::object& element, const std::string& rect_str, std::string ref_id)
{
    theme::object ref_element = element;
    if(ref_id.empty()) {
        ref_id = element.get_id();
    } else {
        ref_element = find_element(ref_id);
    }
    if(ref_element.get_id() == ref_id) {
        SDL_Rect location_ref_rect = ref_element.get_location();
        element.modify_location(rect_str, location_ref_rect);
    }
}
 
void theme::modify(const config& cfg)
{
    std::map<std::string, std::string> title_stash;
    std::vector<theme::menu>::iterator m;
    for(m = menus_.begin(); m != menus_.end(); ++m) {
        if(!m->title().empty() && !m->get_id().empty())
            title_stash[m->get_id()] = m->title();
    }
 
    std::vector<theme::action>::iterator a;
    for(a = actions_.begin(); a != actions_.end(); ++a) {
        if(!a->title().empty() && !a->get_id().empty())
            title_stash[a->get_id()] = a->title();
    }
 
    // Change existing theme objects.
    for(const config& c : cfg.child_range("change")) {
        std::string id = c["id"];
        std::string ref_id = c["ref"];
        theme::object& element = find_element(id);
        if(element.get_id() == id)
            set_object_location(element, c["rect"], ref_id);
    }
 
    // Add new theme objects.
    for(const config& c : cfg.child_range("add")) {
        add_object(cur_spec_width_, cur_spec_height_, c);
    }
 
    // Remove existent theme objects.
    for(const config& c : cfg.child_range("remove")) {
        remove_object(c["id"]);
    }
 
    for(m = menus_.begin(); m != menus_.end(); ++m) {
        if(title_stash.find(m->get_id()) != title_stash.end())
            m->set_title(title_stash[m->get_id()]);
    }
    for(a = actions_.begin(); a != actions_.end(); ++a) {
        if(title_stash.find(a->get_id()) != title_stash.end())
            a->set_title(title_stash[a->get_id()]);
    }
}
 
theme::object& theme::find_element(const std::string& id)
{
    static theme::object empty_object;
    theme::object* res = &empty_object;
 
    auto status_item_it = status_.find(id);
    if(status_item_it != status_.end()) {
        res = status_item_it->second.get();
    }
 
    for(std::vector<theme::panel>::iterator p = panels_.begin(); p != panels_.end(); ++p) {
        if(p->get_id() == id) {
            res = &(*p);
        }
    }
    for(std::vector<theme::label>::iterator l = labels_.begin(); l != labels_.end(); ++l) {
        if(l->get_id() == id) {
            res = &(*l);
        }
    }
    for(std::vector<theme::menu>::iterator m = menus_.begin(); m != menus_.end(); ++m) {
        if(m->get_id() == id) {
            res = &(*m);
        }
    }
    for(std::vector<theme::action>::iterator a = actions_.begin(); a != actions_.end(); ++a) {
        if(a->get_id() == id) {
            res = &(*a);
        }
    }
    if(id == "main-map") {
        res = &main_map_;
    }
    if(id == "mini-map") {
        res = &mini_map_;
    }
    if(id == "palette") {
        res = &palette_;
    }
    if(id == "unit-image") {
        res = &unit_image_;
    }
    return *res;
}
 
const theme::status_item* theme::get_status_item(const std::string& key) const
{
    const auto& i = status_.find(key);
    if(i != status_.end())
        return i->second.get();
    else
        return nullptr;
}
 
const theme::menu* theme::get_menu_item(const std::string& key) const
{
    for(const theme::menu& m : menus_) {
        if(m.get_id() == key)
            return &m;
    }
    return nullptr;
}
 
const theme::action* theme::get_action_item(const std::string& key) const
{
    for(const theme::action& a : actions_) {
        if(a.get_id() == key)
            return &a;
    }
    return nullptr;
}
 
theme::object* theme::refresh_title(const std::string& id, const std::string& new_title)
{
    theme::object* res = nullptr;
 
    for(std::vector<theme::action>::iterator a = actions_.begin(); a != actions_.end(); ++a) {
        if(a->get_id() == id) {
            res = &(*a);
            a->set_title(new_title);
        }
    }
 
    for(std::vector<theme::menu>::iterator m = menus_.begin(); m != menus_.end(); ++m) {
        if(m->get_id() == id) {
            res = &(*m);
            m->set_title(new_title);
        }
    }
 
    return res;
}
 
theme::object* theme::refresh_title2(const std::string& id, const std::string& title_tag)
{
    std::string new_title;
 
    const config& cfg = find_ref(id, cfg_, false);
    if(!cfg[title_tag].empty())
        new_title = cfg[title_tag].str();
 
    return refresh_title(id, new_title + cfg["title_literal"].str());
}
 
void theme::modify_label(const std::string& id, const std::string& text)
{
    theme::label* label = dynamic_cast<theme::label*>(&find_element(id));
    if(!label) {
        LOG_DP << "Theme contains no label called '" << id << "'.";
        return;
    }
    label->set_text(text);
}
 
void theme::set_known_themes(const game_config_view* cfg)
{
    if(cfg) {
        known_themes.clear();
        for(const config& thm : cfg->child_range("theme")) {
            known_themes[thm["id"]] = thm;
        }
    }
}
 
std::vector<theme_info> theme::get_basic_theme_info(bool include_hidden)
{
    std::vector<theme_info> res;
 
    for(const auto& [id, cfg] : known_themes) {
        if(!cfg["hidden"].to_bool(false) || include_hidden) {
            auto& info = res.emplace_back();
            info.id = id;
            info.name = cfg["name"].t_str();
            info.description = cfg["description"].t_str();
        }
    }
 
    return res;
}
 
const config& theme::get_theme_config(const std::string& id)
{
    auto iter = known_themes.find(id);
    if(iter != known_themes.end()) {
        return iter->second;
    }
 
    if (!id.empty()) { // (treat empty id as request for default theme)
        ERR_DP << "Theme '" << id << "' not found."
               << " Falling back to default theme.";
    }
 
    iter = known_themes.find("Default");
    if(iter != known_themes.end()) {
        return iter->second;
    }
 
    ERR_DP << "Default theme not found.";
 
    static config empty;
    return empty;
}