Highlight a data point on all graphs

SetWindow Graph0 hook(HighlightPoint)=HighlightDataPoint_Hook

Make testwave1 = p, testwave2 = sin(x)
Display/N=Graph10 testwave1, testwave2
Display/N=Graph11 testwave1, testwave2
AutoPositionWindow/R=Graph10 Graph11
SetWindow Graph10 hook(HighlightPoint)=HighlightDataPoint_Hook

static Constant HIGHLIGHT_CLICK_MODIFIERS = 2       // Shift key is down

//**
// Window hook function that responds to clicking on a graph
// and then causes a data point to be highlighted.
// @param s
//  An instance of the WMWinHookStruct structure.
// @return
//  A non-zero value if this function handled the event or zero
//  if it did not.
//*
Function HighlightDataPoint_Hook(s)
    STRUCT WMWinHookStruct &s
    Variable hookResult
   
    // Only handle the event if the proper modifier key(s) were pressed.
    if (s.eventCode == 5 && s.eventMod == HIGHLIGHT_CLICK_MODIFIERS)
        // Determine the trace and wave that were clicked on and
        // the point index where the user clicked.
        String hitInfo = TraceFromPixel(s.mouseLoc.h, s.mouseLoc.v, "WINDOW:" + s.winName)
        if (strlen(hitInfo) > 0)
            String traceName = StringByKey("TRACE", hitInfo, ":", ";")
            Variable hitPoint = NumberByKey("HITPOINT", hitInfo, ":", ";")
            if (strlen(traceName) > 0 && numtype(hitPoint) == 0)
                WAVE/Z targetWave = TraceNameToWaveRef(s.winName, traceName)
                if (WaveExists(targetWave))
                    HighlightDataPoint(targetWave, hitPoint, s.winName)
                    hookResult = 1
                endif
            endif
        endif
    endif

    return hookResult
End


//**
// Main utility function that is called to highlight (or remove the highlight from) a
// data point on a wave in a number of graph windows.
//
// @param targetWave
//  A wave reference to the wave the user clicked on.
// @param pointIndex
//  A variable containing the point value at which
//  the tag should be added or removed.
// @param activeGraphName
//  A string containing the name of the graph on which
//  the user clicked.  This graph will always have the tag
//  toggled on or off.
// @param targetGraphList
//  [OPTIONAL]  A string containing a semicolon separated list
//  of graphs which should have a tag added or removed if the
//  specified wave is displayed on the graph.  If this parameter
//  is not specified all graph windows will be acted upon.
// *
Function HighlightDataPoint(targetWave, pointIndex, activeGraphName, [targetGraphList])
    WAVE targetWave
    Variable pointIndex
    String activeGraphName
    String targetGraphList
   
    // If the parameter targetGraphList is not specified, then
    // call a function to get target windows.
    if (ParamIsDefault(targetGraphList))
        targetGraphList = GetTargetGraphList()
    endif
   
    // Make sure that the active graph (the one the user used to
    // trigger this function being called) is included in the list
    // of graphs on which the highlighting of the point should be
    // toggled.
    if (WhichListItem(activeGraphName, targetGraphList, ";") < 0)
        targetGraphList = AddListItem(activeGraphName, targetGraphList, ";", inf)
    endif
   
    Variable numGraphs = ItemsInList(targetGraphList, ";")
    Variable n, traceIndex, numTraces
    String currentGraphName
    String thisWaveFullName
    String targetWaveFullName
    String traceList, currentTraceName
    For (n=0; n<numGraphs; n+=1)
        currentGraphName = StringFromList(n, targetGraphList, ";")
       
        // Make sure this is actually a graph.
        If (WinType(currentGraphName) != 1)
            continue
        endif
       
        // Iterate through the traces on the graph to find
        // if any of them are based on targetWave and if so then
        // append or remove tags on the graph at the specified point.
        // NOTE:  This won't work as expected for traces
        // that are XY pairs.
        traceList = TraceNameList(currentGraphName, ";", 5)     // Include normal graph traces and omit hidden traces
        numTraces = ItemsInList(traceList, ";")
        targetWaveFullName = GetWavesDataFolder(targetWave, 2)
        thisWaveFullName = ""
        traceIndex = 0
        For (traceIndex = 0; traceIndex < numTraces; traceIndex +=1)
            currentTraceName = StringFromList(traceIndex, traceList, ";")
            WAVE/Z thisWave = TraceNameToWaveRef(currentGraphName, currentTraceName)

            // If thisWave is NULL for any reason, skip it.
            if (!WaveExists(thisWave))
                continue
            endif
           
            // Determine if targetWave and thisWave are the same wave.
            thisWaveFullName = GetWavesDataFolder(thisWave, 2)
            if (cmpstr(thisWaveFullName, targetWaveFullName) == 0)
                // Toggle the presence of tags for the given point on the specified graphs.
                RemoveOrAddTagToTrace(currentGraphName, currentTraceName, pointIndex)
            endif
        EndFor
    EndFor
End

//**
// Toggles the presence of a tag on the specified trace at the specified point.
//
// @param graphName
//  A string containing the full name of the graph.
// @param traceName
//  A string containing the name of the trace.
// @param pointIndex
//  A variable containing the point value at which
//  the tag should be added or removed.
//
// @return
//  1 if a tag was removed, 0 if it was added, or NaN if there was
//  an error, such as an invalid graph or trace name.
//*
Function RemoveOrAddTagToTrace(graphName, traceName, pointIndex)
    String graphName
    String traceName
    Variable pointIndex
   
    // Make sure graph exists.
    if (WinType(graphName) != 1)
        return NaN
    endif
   
    // Make sure trace is on graph
    if (strlen(TraceInfo(graphName, traceName, 0)) < 1)
        return NaN
    endif
   
    // So that we don't delete an annotation that has been placed
    // on the graph outside of this function, filter the list
    // of all annotations so we only process ones
    // with names beginning with "highlight_tag_"
    String listOfAnnotations = AnnotationList(graphName)
    listOfAnnotations = ListMatch(listOfAnnotations, "highlight_tag_*", ";")

    Variable numAnnotations = ItemsInList(listOfAnnotations, ";")
    String currentAnnotationName, info
    Variable n, attachedPoint
    Variable removedATag

    // Determine if there is already a tag on the trace at the
    // specified point.
    For (n=0; n<numAnnotations; n+=1)
        currentAnnotationName = StringFromList(n, listOfAnnotations, ";")
        info = AnnotationInfo(graphName, currentAnnotationName)
        if (strlen(info) > 0)
            // If this isn't a tag then ignore it.
            if (cmpstr(StringByKey("TYPE", info, ":", ";"), "Tag") == 0)
                // If this tag isn't attached to traceName, ignore it.
                if (cmpstr(StringByKey("YWAVE", info, ":", ";"), traceName) == 0)
                    // If the tag isn't attached to point pointIndex, ignore it.
                    attachedPoint = NumberByKey("ATTACHX", info, ":", ";")
                    if (numtype(attachedPoint) == 0 && attachedPoint == pointIndex)
                        // Tag is already attached to the given point on the given
                        // graph and trace, so remove it.
                        Tag/W=$(graphName)/N=$(currentAnnotationName)/K
                        removedATag = 1
                    endif
                endif
            endif
        endif
    EndFor
   
    // If we didn't just remove one or more tags, then we need to add a tag
    // to the specified trace.  If we did remove a tag, then just return.
    if (!removedATag)
        // Add a tag.
        String newTagName = UniqueName("highlight_tag_", 14, 0, graphName)
        Tag/W=$(graphName)/C/N=$(newTagName)/F=0/B=1/H={0,2,10}/X=0.00/Y=0.00/L=0/TL=0 $(traceName), pointIndex, "\\W519"
    endif
    return removedATag
End

//**
// Get a list of target windows.
//
// @TODO:  This could be expanded so that
// child windows were also returned.  As is, subwindows
// will not be affected.
//
// @return
// A string with a semicolon separated list of graph
// window names.
//*
Function/S GetTargetGraphList()
    String targetGraphList = ""
   
    targetGraphList = WinList("*", ";", "WIN:1")        // All graph windows.
    return targetGraphList
End