feat(key_binder): toggle the switch defined at index toggle: '@n'

Closes #554

src/rime/gear/key_binder.cc

@@ -5,6 +5,7 @@
 // 2011-11-23 GONG Chen <chen.sst@gmail.com>
 //
 #include <algorithm>
+#include <boost/lexical_cast.hpp>
 #include <rime/common.h>
 #include <rime/composition.h>
 #include <rime/context.h>
@@ -77,12 +78,27 @@ static void radio_select_option(Context* ctx,
       });
 }
 
+inline static bool is_switch_index(const string& option) {
+  return !option.empty() && option.front() == '@';
+}
+
+static Switches::SwitchOption switch_by_index(Switches& switches,
+                                              const string& option) {
+  try {
+    size_t index = boost::lexical_cast<size_t>(option.substr(1));
+    return switches.ByIndex(index);
+  } catch (...) {}
+  return {};
+}
+
 static void toggle_option(Engine* engine, const string& option) {
   if (!engine)
     return;
   Context* ctx = engine->context();
   Switches switches(engine->schema()->config());
-  auto the_option = switches.OptionByName(option);
+  auto the_option = is_switch_index(option)
+                    ? switch_by_index(switches, option)
+                    : switches.OptionByName(option);
   if (the_option.found() && the_option.type == Switches::kRadioGroup) {
     auto selected_option = switches.FindRadioGroupOption(
         the_option.the_switch,
@@ -102,7 +118,10 @@ static void toggle_option(Engine* engine, const string& option) {
       radio_select_option(ctx, next_option);
     }
   } else {  // toggle
-    ctx->set_option(option, !ctx->get_option(option));
+    // option can be an index. use the found option name, or an arbitrary
+    // option name specified by caller.
+    auto option_name = the_option.found() ? the_option.option_name : option;
+    ctx->set_option(option_name, !ctx->get_option(option_name));
   }
 }
 

src/rime/switches.cc

@@ -3,64 +3,83 @@
 
 namespace rime {
 
-Switches::SwitchOption Switches::FindOption(
+inline static int reset_value(ConfigItemRef& item) {
+  auto reset = item["reset"];
+  return reset.IsValue() ? reset.ToInt() : -1;
+}
+
+Switches::SwitchOption Switches::FindOptionFromConfigItem(
+    ConfigItemRef& item,
+    size_t switch_index,
     function<FindResult (SwitchOption option)> callback) {
-  auto switches = (*config_)["switches"];
-  if (!switches.IsList())
-    return {};
-  for (size_t i = 0; i < switches.size(); ++i) {
-    auto item = switches[i];
-    if (!item.IsMap())
-      continue;
-    auto the_switch = As<ConfigMap>(*item);
-    auto reset = item["reset"];
-    int reset_value = reset.IsValue() ? reset.ToInt() : -1;
-    auto name = item["name"];
-    if (name.IsValue()) {
+  auto the_switch = As<ConfigMap>(*item);
+  auto name = item["name"];
+  auto options = item["options"];
+  if (name.IsValue()) {
+    SwitchOption option{
+      the_switch,
+      kToggleOption,
+      name.ToString(),
+      reset_value(item),
+      switch_index,
+    };
+    if (callback(option) == kFound)
+      return option;
+  } else if (options.IsList()) {
+    for (size_t option_index = 0; option_index < options.size();
+         ++option_index) {
       SwitchOption option{
         the_switch,
-        kToggleOption,
-        name.ToString(),
-        reset_value,
-        i,
+        kRadioGroup,
+        options[option_index].ToString(),
+        reset_value(item),
+        switch_index,
+        option_index,
       };
       if (callback(option) == kFound)
         return option;
-      continue;
-    }
-    auto options = item["options"];
-    if (options.IsList()) {
-      for (size_t j = 0; j < options.size(); ++j) {
-        SwitchOption option{
-          the_switch,
-          kRadioGroup,
-          options[j].ToString(),
-          reset_value,
-          i,
-          j,
-        };
-        if (callback(option) == kFound)
-          return option;
-      }
     }
   }
   return {};
 }
 
+Switches::SwitchOption Switches::FindOption(
+    function<FindResult (SwitchOption option)> callback) {
+  auto switches = (*config_)["switches"];
+  if (!switches.IsList())
+    return {};
+  for (size_t switch_index = 0; switch_index < switches.size();
+       ++switch_index) {
+    auto item = switches[switch_index];
+    if (!item.IsMap())
+      continue;
+    auto option = FindOptionFromConfigItem(item, switch_index, callback);
+    if (option.found())
+      return option;
+  }
+  return {};
+}
+
 Switches::SwitchOption Switches::OptionByName(const string& option_name) {
   return FindOption([&option_name](SwitchOption option) {
     return option.option_name == option_name ? kFound : kContinue;
   });
 }
 
-an<ConfigMap> Switches::ByIndex(size_t switch_index) {
+Switches::SwitchOption Switches::ByIndex(size_t switch_index) {
   auto switches = (*config_)["switches"];
   if (!switches.IsList())
-    return nullptr;
+    return {};
   if (switches.size() <= switch_index)
-    return nullptr;
+    return {};
   auto item = switches[switch_index];
-  return As<ConfigMap>(*item);
+  return FindOptionFromConfigItem(
+      item,
+      switch_index,
+      // return the very first found option.
+      [](SwitchOption option) {
+        return kFound;
+      });
 }
 
 Switches::SwitchOption Switches::Cycle(const SwitchOption& current) {

src/rime/switches.h

@@ -6,6 +6,7 @@
 namespace rime {
 
 class Config;
+class ConfigItemRef;
 class ConfigMap;
 class ConfigValue;
 
@@ -43,7 +44,9 @@ class Switches {
 
   SwitchOption OptionByName(const string& option_name);
 
-  an<ConfigMap> ByIndex(size_t switch_index);
+  // Returns the switch option defined at switch_index.
+  // If the swtich is a radio group, return the first option in the group.
+  SwitchOption ByIndex(size_t switch_index);
 
   static SwitchOption Cycle(const SwitchOption& option);
 
@@ -59,6 +62,11 @@ class Switches {
   an<ConfigValue> GetStateLabel(const string& option_name, int state);
 
  private:
+  SwitchOption FindOptionFromConfigItem(
+      ConfigItemRef& item,
+      size_t switch_index,
+      function<FindResult (SwitchOption option)> callback);
+
   Config* config_;
 };