cameraMessageCmd/cameraMessageCmd.cpp

//-
// ===========================================================================
// Copyright 2018 Autodesk, Inc. All rights reserved.
//
// Use of this software is subject to the terms of the Autodesk license
// agreement provided at the time of installation or download, or which
// otherwise accompanies this software in either electronic or hard copy form.
// ===========================================================================
//+

/* 

    file : cameraMessageCmd.cpp
    class: cameraMessageCmd
    ----------------------
    
    This plugin demonstrates each of the camera manipulation callbacks available
    in the Maya API.  Callbacks are added to nodes by invoking the command:

        cameraMessageCmd <node 1> [<node 2> ...]
    
    This command will register 2 callbacks on the nodes.

    1) MNodeMessage::addBeginManipulationCallback is used to register a camera
       manipulation beginning callback on the nodes.  This callback is executed
       once an interactive manipulation of a camera is beginning, such as tumble
       or zoom.  
    
    1) MNodeMessage::addEndManipulationCallback is used to register a camera
       manipulation ending callback on the nodes.  This callback is executed
       once an interactive manipulation of a camera is completed.

    Here is an example of the expected behavior of the callbacks registered on 
    "perspShape", and is then manipulated.

    After loading this plugin, run:
        select perspShape;
        cameraMessageCmd;
    
    The following messages will be displayed:

        // Adding payload 12345.5 to beginManipulation callback for node perspShape // 
        // Adding payload 54321.5 to endManipulation callback for node perspShape // 
    
    When beginning to tumble a camera, this message will be displayed:
    
        // Beginning-of-Manipulation callback for node: perspShape // 
        // Found Payload: 12345.5 // 
        
    When the tumble of a camera is finished, this message will be displayed:

        // End-of-Manipulation callback for node: perspShape // 
        // Found Payload: 54321.5 // 

*/

#include <maya/MFnPlugin.h>
#include <maya/MStatus.h>
#include <maya/MPxCommand.h>
#include <maya/MMessage.h>
#include <maya/MCameraMessage.h>
#include <maya/MDagPath.h>
#include <maya/MGlobal.h>
#include <maya/MArgList.h>
#include <maya/MArgDatabase.h>
#include <maya/MSyntax.h>
#include <maya/MSelectionList.h>
#include <maya/MFnDependencyNode.h>
#include <maya/MCallbackIdArray.h>

// Syntax string definitions

class cameraMessageCmd : public MPxCommand
{
    public:
        MStatus doIt( const MArgList& ) override;

        static void *creator();
        static MSyntax newSyntax();

        static void removeCallbacks();

        // callback functions.
        static void beginManipulationCB(MObject& node, void* clientData);   
        static void endManipulationCB(MObject& node, void* clientData);

    private:
        static MCallbackIdArray callbackIds;
        static bool nodeRemovedCBRegistered;
};

MCallbackIdArray cameraMessageCmd::callbackIds;
bool cameraMessageCmd::nodeRemovedCBRegistered = false;

MStatus cameraMessageCmd::doIt( const MArgList& args )
{
    MStatus status = MS::kSuccess;

    MArgDatabase argData(syntax(), args);
    MSelectionList objects;
    argData.getObjects(objects);

    for (unsigned int i = 0; i < objects.length(); i++) {
        MObject node;
        objects.getDependNode(i, node);

        double* payloadBegin = new double(12345.5);
        MDagPath dagPath;
        status = objects.getDagPath(i, dagPath);
        MGlobal::displayInfo( (MString("Adding payload ") + *payloadBegin) + MString(" to beginManipulation callback for node ") + dagPath.partialPathName());
        callbackIds.append(
            MCameraMessage::addBeginManipulationCallback (node, beginManipulationCB, payloadBegin, &status)
        );
        if (!status) {
            MGlobal::displayWarning("Could not attach beginManipulation callback for node.");
            continue;
        }

        double* payloadEnd = new double(54321.5);
        MGlobal::displayInfo( (MString("Adding payload ") + *payloadEnd) + MString(" to endManipulation callback for node ") + dagPath.partialPathName());
        //  Add some user data to this callback, 
        callbackIds.append(
            MCameraMessage::addEndManipulationCallback (node, endManipulationCB, payloadEnd, &status)
        );
        if (!status) {
            MGlobal::displayWarning("Could not attach endManipulation callback for node.");
            continue;
        }
    }
    
    return status;
}


void* cameraMessageCmd::creator() 
{   
    return new cameraMessageCmd;
}

MSyntax cameraMessageCmd::newSyntax() {
    MSyntax syntax;
    syntax.setObjectType(MSyntax::kSelectionList);
    syntax.setMinObjects(1);
    syntax.useSelectionAsDefault(true);
    return syntax;
}

void cameraMessageCmd::beginManipulationCB(MObject& node, void* clientData) {
    MFnDependencyNode nodeFn(node);
    MGlobal::displayInfo(MString("Beginning-of-Manipulation callback for node: ") + nodeFn.name());

    double* payloadA = static_cast<double*>(clientData);
    if(payloadA)
    {
        MGlobal::displayInfo(MString("Found Payload: ") + (*payloadA));
    }
}

void cameraMessageCmd::endManipulationCB(MObject& node, void* clientData) {
    MFnDependencyNode nodeFn(node);
    MGlobal::displayInfo(MString("End-of-Manipulation callback for node: ") + nodeFn.name());

    double* payloadB = static_cast<double*>(clientData);
    if(payloadB)
    {
        MGlobal::displayInfo(MString("Found Payload: ") + (*payloadB));
    }
}

void cameraMessageCmd::removeCallbacks() {
    MMessage::removeCallbacks(callbackIds);
}

// standard initialize and uninitialize functions

MStatus initializePlugin(MObject obj)
{
    MFnPlugin pluginFn(obj, PLUGIN_COMPANY, "6.0");

    MStatus status;
    status = pluginFn.registerCommand("cameraMessageCmd", cameraMessageCmd::creator, cameraMessageCmd::newSyntax);

    if( !status)
        status.perror("register Command failed");

    return status;
}


MStatus uninitializePlugin ( MObject obj )
{
    MFnPlugin pluginFn(obj);
    MStatus status = MS::kSuccess;

    cameraMessageCmd::removeCallbacks();

    status = pluginFn.deregisterCommand("cameraMessageCmd");

    return status;
}