HUSD_OutputProcessor.h

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/*
 * Copyright 2019 Side Effects Software Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

#ifndef __HUSD_OutputProcessor_h__
#define __HUSD_OutputProcessor_h__

#include "HUSD_API.h"
#include <UT/UT_Function.h>
#include <UT/UT_SharedPtr.h>
#include <UT/UT_StringArray.h>
#include <UT/UT_StringMap.h>

class UT_Options;
class UT_String;
class OP_Node;
class PI_EditScriptedParms;

// ============================================================================ 
/// Performs processing on a USD output path during a save operation.
///
class HUSD_API HUSD_OutputProcessor
{
public:
    /// This enum describes the return value from the shouldSave method.
    /// This enum must be kept in sync with the values in outputprocessors.py,
    /// in the OutputProcessor class.
    enum HUSD_ShouldSave {
        SHOULD_SAVE_FALSE = 0,
        SHOULD_SAVE_TRUE = 1,
        SHOULD_SAVE_NO_OPINION = 2
    };

    /// Standard virtual destructor for this abstract base class.
    virtual             ~HUSD_OutputProcessor() = default;

    virtual void         beginSave(OP_Node *config_node,
                                const UT_Options &config_overrides,
                                OP_Node *lop_node,
                                fpreal t,
                                const UT_Options &stage_variables,
                                UT_String &error)
                         { }

    virtual void         endSave(OP_Node *config_node,
                                const UT_Options &config_overrides,
                                OP_Node *lop_node,
                                fpreal t,
                                const UT_Options &stage_variables,
                                const UT_StringArray &saved_paths,
                                const UT_String &error_messages,
                                UT_String &error)
                         { }

    virtual bool         processSavePath(const UT_StringRef &asset_path,
                                const UT_StringRef &referencing_layer_path,
                                bool asset_is_layer,
                                UT_String &newpath,
                                UT_String &error)
                         { return false; }

    virtual bool         processReferencePath(const UT_StringRef &asset_path,
                                const UT_StringRef &referencing_layer_path,
                                bool asset_is_layer,
                                UT_String &newpath,
                                UT_String &error)
                         { return false; }

    virtual bool         processReferenceExpression(
                                 const UT_StringRef &asset_expression,
                                 const UT_StringRef &referencing_layer_path,
                                 bool asset_is_layer,
                                 UT_String &newpath,
                                 UT_String &error)
                         { return false; }

    virtual bool         processLayer(const UT_StringRef &identifier,
                                UT_String &error)
                         { return false; }

    virtual HUSD_ShouldSave shouldSave(const UT_StringRef &save_path,
                                const UT_StringRef &identifier,
                                UT_String &error)
                         { return SHOULD_SAVE_NO_OPINION; }

    virtual UT_StringHolder              displayName() const = 0;
    virtual const PI_EditScriptedParms  *parameters() const = 0;

    virtual bool         hidden() const
                         { return false; }
};
typedef UT_SharedPtr<HUSD_OutputProcessor> HUSD_OutputProcessorPtr;
typedef UT_Array<HUSD_OutputProcessorPtr> HUSD_OutputProcessorArray;
typedef UT_Function<HUSD_OutputProcessorPtr ()> HUSD_OutputProcessorFactory;

// ============================================================================ 
/// Keeps a list of known processors that can translate a USD output path
/// during a save operation.
///
class HUSD_API HUSD_OutputProcessorRegistry
{
public:
    /// Returns a singelton instance.
    static HUSD_OutputProcessorRegistry &get();

    /// Returns a list of the names of all available processors.
    UT_StringArray           processorNames() const;

    /// Returns the processor that matches the supplied name.
    HUSD_OutputProcessorPtr  createProcessor(const UT_StringRef &name) const;

    /// Adds the processor to the list of known processors.
    void                     registerOutputProcessor(
                                    const UT_StringHolder &name,
                                    const HUSD_OutputProcessorFactory &factory);

    /// Removes the processor from the list of known processors.
    void                     unregisterOutputProcessor(
                                    const UT_StringRef &name);

    /// Removes all processors from the registry. Should only be called on
    /// shutdown of the process.
    void                     clear();

private:
    /// Map of known output processors, keyed by their internal names.
    UT_StringMap<HUSD_OutputProcessorFactory>    myProcessorFactories;
};

HUSD_API HUSD_OutputProcessorPtr
HUSDcreateOutputProcessor(const UT_StringRef &name);
HUSD_API UT_StringHolder
HUSDremoveHfsOutputProcessorName();

#endif