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authorTiger Wang <ziwei.tiger@outlook.com>2020-09-08 10:46:16 +0200
committerTiger Wang <ziwei.tiger@outlook.com>2020-12-21 01:11:34 +0100
commit742e27ad2f037205285e475be487ec9ed874ca91 (patch)
tree3218d3c2791e823c88a294ba7fdb10035c8fbb9b /src/Bindings/BlockTypeRegistry.h
parentEnable LOS checks for Hostile Mobs. (diff)
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Diffstat (limited to 'src/Bindings/BlockTypeRegistry.h')
-rw-r--r--src/Bindings/BlockTypeRegistry.h216
1 files changed, 216 insertions, 0 deletions
diff --git a/src/Bindings/BlockTypeRegistry.h b/src/Bindings/BlockTypeRegistry.h
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+++ b/src/Bindings/BlockTypeRegistry.h
@@ -0,0 +1,216 @@
+#pragma once
+
+
+
+
+
+#include <map>
+#include <functional>
+
+
+
+
+
+// fwd:
+class cBlockHandler;
+class BlockState;
+
+
+
+
+
+/** Complete information about a single block type.
+The BlockTypeRegistry uses this structure to store the registered information. */
+class BlockInfo
+{
+public:
+
+ /** Callback is used to query block hints dynamically, based on the current BlockState.
+ Useful for example for redstone lamps that can be turned on or off. */
+ using HintCallback = std::function<AString(const AString & aTypeName, const BlockState & aBlockState)>;
+
+
+ /** Creates a new instance with the specified BlockTypeName and handler / hints / callbacks.
+ aPluginName specifies the name of the plugin to associate with the block type (to allow unload / reload). */
+ BlockInfo(
+ const AString & aPluginName,
+ const AString & aBlockTypeName,
+ std::shared_ptr<cBlockHandler> aHandler,
+ const std::map<AString, AString> & aHints = std::map<AString, AString>(),
+ const std::map<AString, HintCallback> & aHintCallbacks = std::map<AString, HintCallback>()
+ );
+
+
+ /** Retrieves the value associated with the specified hint for this specific BlockTypeName and BlockState.
+ Queries hint callbacks first, then static hints if a callback doesn't exist.
+ Returns an empty string if hint not found at all. */
+ AString hintValue(
+ const AString & aHintName,
+ const BlockState & aBlockState
+ );
+
+ // Simple getters:
+ const AString & pluginName() const { return m_PluginName; }
+ const AString & blockTypeName() const { return m_BlockTypeName; }
+ std::shared_ptr<cBlockHandler> handler() const { return m_Handler; }
+
+ /** Sets (creates or updates) a static hint.
+ Hints provided by callbacks are unaffected by this - callbacks are "higher priority", they overwrite anything set here.
+ Logs an info message if the hint is already provided by a hint callback. */
+ void setHint(const AString & aHintKey, const AString & aHintValue);
+
+ /** Removes a hint.
+ Silently ignored if the hint hasn't been previously set. */
+ void removeHint(const AString & aHintKey);
+
+
+private:
+
+ /** The name of the plugin that registered the block. */
+ AString m_PluginName;
+
+ /** The name of the block type, such as "minecraft:redstone_lamp" */
+ AString m_BlockTypeName;
+
+ /** The callbacks to call for various interaction. */
+ std::shared_ptr<cBlockHandler> m_Handler;
+
+ /** Optional static hints for any subsystem to use, such as "IsSnowable" -> "1".
+ Hint callbacks are of higher priority than m_Hints - if a hint is provided by a m_HintCallback, its value in m_Hints is ignored. */
+ std::map<AString, AString> m_Hints;
+
+ /** The callbacks for dynamic evaluation of hints, such as "LightValue" -> function(BlockTypeName, BlockState).
+ Hint callbacks are of higher priority than m_Hints - if a hint is provided by a m_HintCallback, its value in m_Hints is ignored. */
+ std::map<AString, HintCallback> m_HintCallbacks;
+};
+
+
+
+
+
+/** Stores information on all known block types.
+Can dynamically add and remove block types.
+Block types are identified using BlockTypeName.
+Supports unregistering and re-registering the same type by the same plugin.
+Stores the name of the plugin that registered the type, for better plugin error messages ("already registered in X")
+and so that we can unload and reload plugins. */
+class BlockTypeRegistry
+{
+public:
+ // fwd:
+ class AlreadyRegisteredException;
+ class NotRegisteredException;
+
+
+ /** Creates an empty new instance of the block type registry */
+ BlockTypeRegistry() = default;
+
+ /** Registers the specified block type.
+ If the block type already exists and the plugin is the same, updates the registration.
+ If the block type already exists and the plugin is different, throws an AlreadyRegisteredException. */
+ void registerBlockType(
+ const AString & aPluginName,
+ const AString & aBlockTypeName,
+ std::shared_ptr<cBlockHandler> aHandler,
+ const std::map<AString, AString> & aHints = std::map<AString, AString>(),
+ const std::map<AString, BlockInfo::HintCallback> & aHintCallbacks = std::map<AString, BlockInfo::HintCallback>()
+ );
+
+ /** Returns the registration information for the specified BlockTypeName.
+ Returns nullptr if BlockTypeName not found. */
+ std::shared_ptr<BlockInfo> blockInfo(const AString & aBlockTypeName);
+
+ /** Removes all registrations done by the specified plugin. */
+ void removeAllByPlugin(const AString & aPluginName);
+
+ /** Sets (adds or overwrites) a single Hint value for a BlockType.
+ Throws NotRegisteredException if the BlockTypeName is not registered. */
+ void setBlockTypeHint(
+ const AString & aBlockTypeName,
+ const AString & aHintKey,
+ const AString & aHintValue
+ );
+
+ /** Removes a previously registered single Hint value for a BlockType.
+ Throws NotRegisteredException if the BlockTypeName is not registered.
+ Silently ignored if the Hint hasn't been previously set. */
+ void removeBlockTypeHint(
+ const AString & aBlockTypeName,
+ const AString & aHintKey
+ );
+
+
+private:
+
+ /** The actual block type registry.
+ Maps the BlockTypeName to the BlockInfo instance. */
+ std::map<AString, std::shared_ptr<BlockInfo>> m_Registry;
+
+ /** The CS that protects m_Registry against multithreaded access. */
+ cCriticalSection m_CSRegistry;
+};
+
+
+
+
+
+/** The exception thrown from BlockTypeRegistry::registerBlockType() if the same block type is being registered from a different plugin. */
+class BlockTypeRegistry::AlreadyRegisteredException: public std::runtime_error
+{
+ using Super = std::runtime_error;
+
+public:
+
+ /** Creates a new instance of the exception that provides info on both the original registration and the newly attempted
+ registration that caused the failure. */
+ AlreadyRegisteredException(
+ const std::shared_ptr<BlockInfo> & aPreviousRegistration,
+ const std::shared_ptr<BlockInfo> & aNewRegistration
+ );
+
+ // Simple getters:
+ std::shared_ptr<BlockInfo> previousRegistration() const { return m_PreviousRegistration; }
+ std::shared_ptr<BlockInfo> newRegistration() const { return m_NewRegistration; }
+
+
+private:
+
+ std::shared_ptr<BlockInfo> m_PreviousRegistration;
+ std::shared_ptr<BlockInfo> m_NewRegistration;
+
+
+ /** Returns the general exception message formatted by the two registrations.
+ The output is used when logging. */
+ static AString message(
+ const std::shared_ptr<BlockInfo> & aPreviousRegistration,
+ const std::shared_ptr<BlockInfo> & aNewRegistration
+ );
+};
+
+
+
+
+
+/** The exception thrown from BlockTypeRegistry::setBlockTypeHint() if the block type has not been registered before. */
+class BlockTypeRegistry::NotRegisteredException: public std::runtime_error
+{
+ using Super = std::runtime_error;
+
+public:
+
+ /** Creates a new instance of the exception that provides info on both the original registration and the newly attempted
+ registration that caused the failure. */
+ NotRegisteredException(
+ const AString & aBlockTypeName,
+ const AString & aHintKey,
+ const AString & aHintValue
+ );
+
+ // Simple getters:
+ const AString & blockTypeName() const { return m_BlockTypeName; }
+
+
+private:
+
+ const AString m_BlockTypeName;
+};