######################
#
# FLOWPATHxml.SML
#
# Demonstration SML ToolScript using an XML specification to create the
# toolscript dialog window.
#
# Requires TNTmips Version 7.0
# Get the lastest version of this toolscript from our website www.microimages.com

#####################

# View ToolScript 
# 
# The following symbols are predefined 
#    class VIEW View            {use to access the view the tool script is attached to} 
#    class GROUP Group          {use to access the group being viewed if the script is run from a group view} 
#    class LAYOUT Layout        {use to access the layout being viewed if the script is run from a layout view} 
#    number ToolIsActive        Will be 0 if tool is inactive or 1 if tool is active 
# 

# To use this ToolScript add one or more DEM's to your Group Display
# The DEM you actually want to use in the watershed process should be the first layer in the group
# i.e. the layer at the bottom of the Group Controls window if you want to change the DEM that you were using
# switch from the ToolScript tool to some other tool and move that DEM to the bottom of the Group Controls
# and reactivate the Toolscript it will ask if you want to switch the input DEM 
# you can run several successive flowpaths and buffer zones keeping the same DEM

array seedx[10];
array seedy[10];
class WATERSHED w;
numeric numpts, i;
class RASTER DEM;
numeric firstpass;
class VECTORLAYER VecBuf;
class VECTORLAYER VecFlow;
class VECTORLAYER BasinLayer;
class VECTORLAYER BoundaryLayer;
class RasterLayer DEMLayer;
numeric haslayers;
class XMLDOC doc;
class XMLNODE dlgnode;
class GUI_DLG dlgform;
class GUI_CTRL_COLORBUTTON bocolorbtn, fcolorbtn, bacolorbtn, bucolorbtn;
numeric setDefaultWhenClose;
class VECTOR VectIn;
class VECTOR VecBoundary;
class POINT2D pt;
array xPoints[10],yPoints[10];
numeric xMax,yMax,xMin,yMin;
array xhold[10], yhold[10];
class PromptNum PromptDistance;
class VECTOR VECFLOW, VECFLOW2;
string tempfilename$, demFilename$, demObjname$;
string flowpathFilename$, flowpathObjname$;
string userflowpathFilename$, userflowpathObjname$;
string userBasinFilename$, userBasinObjname$; 
numeric tempinode, demInode, flowpathInode;
string tempobjname$;
class Color bocolor;
class Color fcolor;
class Color bucolor;
class Color bacolor;


# function to create a status to attach popup messages to
# the advantage is that if the process is quick dialog won't pop in/out
# requires tntdisp 20001012 or later
proc StatusStart() {
	class StatusHandle status;
	class StatusContext context;
	status = StatusDialogCreate();
	context = StatusContextCreate(status);
}

proc StatusStop() {
		StatusContextDestroy(context);
		StatusDialogDestroy(status);
}

# called when user presses save button on dialog
# if something wasn't calculated by choice output object is empty
proc DoSave() {
	local numeric answer, destParentInode, userflowpathInode, userbasinInode;
	local string destFilename$;
	local vector Buffer2;
	if (haslayers) {
		answer = PopupYesNo("Save Output Objects?");
		if (answer) {
			#Get output Filename
			destFilename$ = GetOutputFileName(" ","Watershed output","rvc");
			CreateProjectFile(destFilename$,"Watershed output");
			destParentInode = 0;
			userflowpathInode = ObjectNumber(userflowpathFilename$,userflowpathObjname$,"VECTOR");
			CopyObject(userflowpathFilename$,userflowpathInode,destFilename$,destParentInode);

			CreateVector(Buffer2,destFilename$,"Buffer","Flow path buffer zone","Polygonal");
			Buffer2 = VectorToBufferZone(VectIn,"line",PromptDistance.value,"meters");

			userbasinInode = ObjectNumber(userBasinFilename$,userBasinObjname$,"VECTOR");
			CopyObject(userBasinFilename$,userbasinInode,destFilename$,destParentInode);
		}
	}
}

# function to remove layers from display
proc DoRemove() {
	if (haslayers) {
		View.DisableRedraw = 1;
		#save user's changes to colors;
		fcolor.red = VecFlow.Line.NormalStyle.Color.red;
		fcolor.green = VecFlow.Line.NormalStyle.Color.green;
		fcolor.blue = VecFlow.Line.NormalStyle.Color.blue;
		bucolor.red = VecBuf.Line.NormalStyle.Color.red;
		bucolor.green = VecBuf.Line.NormalStyle.Color.green;
		bucolor.blue = VecBuf.Line.NormalStyle.Color.blue;
		bacolor.red = BasinLayer.Line.NormalStyle.Color.red;
		bacolor.green = BasinLayer.Line.NormalStyle.Color.green;
		bacolor.blue = BasinLayer.Line.NormalStyle.Color.blue;
		bocolor.red = BoundaryLayer.Line.NormalStyle.Color.red;
		bocolor.green = BoundaryLayer.Line.NormalStyle.Color.green;
		bocolor.blue = BoundaryLayer.Line.NormalStyle.Color.blue;
		VecFlow = LayerDestroy(VecFlow);
		VecBuf = LayerDestroy(VecBuf);
		BasinLayer = LayerDestroy(BasinLayer);
		View.DisableRedraw = 0;
		haslayers = 0;
		}
}
# called when user presses remove button on dialog
proc cbDoRemove() {
	DoRemove();
	ViewRedrawIfNeeded(View);
}

# called when the user presses the set button on dialog
# sets the number of seedpoints to use
proc DoSet() {
	numpts = PopupNum("Enter number of seed points", numpts,1,10);
	i = 1;
	}

# Close the window, switching to default tool
# called when user presses close button and when clicks x in dialog
proc DoClose() {
	if (setDefaultWhenClose) {
		setDefaultWhenClose = false;
		View.SetDefaultTool();
	}
}


# Called when new flow path color is selected from toolscript dialog
proc OnChangefcolor () {
	fcolor = fcolorbtn.GetColor();
	if (GroupGetLayerByName(Group,VecFlow.Name) != 0) {
		View.DisableRedraw = 1;
		VecFlow.Line.NormalStyle.Color.red = fcolor.red;
		VecFlow.Line.NormalStyle.Color.green = fcolor.green;
		VecFlow.Line.NormalStyle.Color.blue = fcolor.blue;
		View.DisableRedraw = 0;
		ViewRedraw(View);
		}
	}

# Called when new basin color is selected from toolscript dialog
proc OnChangebacolor () {
	bacolor = bacolorbtn.GetColor();
	if (GroupGetLayerByName(Group,BasinLayer.Name) != 0) {
		View.DisableRedraw = 1;
		BasinLayer.Line.NormalStyle.Color.red = bacolor.red;
		BasinLayer.Line.NormalStyle.Color.green = bacolor.green;
		BasinLayer.Line.NormalStyle.Color.blue = bacolor.blue;
		View.DisableRedraw = 0;
		ViewRedraw(View);
		}
	}

# Called when new buffer zone color is selected from toolscript dialog
proc OnChangebucolor () {
	bucolor = bucolorbtn.GetColor();
	if (GroupGetLayerByName(Group,VecBuf.Name) != 0) {
		View.DisableRedraw = 1;
		VecBuf.Line.NormalStyle.Color.red = bucolor.red;
		VecBuf.Line.NormalStyle.Color.green = bucolor.green;
		VecBuf.Line.NormalStyle.Color.blue = bucolor.blue;
		View.DisableRedraw = 0;
		ViewRedraw(View);
		}
	}

# Called when new extents box color is selected from toolscript dialog
proc OnChangebocolor () {
	bocolor = bocolorbtn.GetColor();
	# PopupMessage(sprintf("Extents box red = %d, green = %d, blue = %d",bocolor.red,bocolor.green,bocolor.blue))
	View.DisableRedraw = 1;
	BoundaryLayer.Poly.Select.Mode = "None";
	BoundaryLayer.Line.NormalStyle.Color.red = bocolor.red;
	BoundaryLayer.Line.NormalStyle.Color.green = bocolor.green;
	BoundaryLayer.Line.NormalStyle.Color.blue = bocolor.blue;

	View.DisableRedraw = 0;
	ViewRedraw(View);
	}


# Called the first time the tool is activated. 
# If the tool implements a dialog it should be created (but not displayed) here. 
func OnInitialize () {

	local numeric err;

	# set up initial colors for vector layers
	bocolor.red = 100;
	bocolor.green = 0;
	bocolor.blue = 0;

	fcolor.red = 0;
	fcolor.green = 0;
	fcolor.blue = 100;

	bucolor.red = 100;
	bucolor.green = 100;
	bucolor.blue = 0;

	bacolor.red = 0;
	bacolor.green = 100;
	bacolor.blue = 0;

	StatusStart();

		# get the raster input DEM
		if (Group.FirstLayer.Type == "Raster") {
			DispGetRasterFromLayer(DEM,Group.FirstLayer);
			DEMLayer = Group.FirstLayer;
			}
		else {
			PopupString("First Layer must be a raster object for Watershed Toolscript");
			WaitForExit();
			}

		demFilename$ = GetObjectFileName(DEM);
		demInode = GetObjectNumber(DEM);
		demObjname$ = GetObjectName(demFilename$,demInode);

		# Initialize watershed object (assigns object handle)
		w = WatershedInit(demFilename$,demObjname$);

		# Fill all depressions in DEM and compute watersheds.
		# a depressionless version of the DEM is automatically created
		# as a temporary internal object associated with watershed handle w
		WatershedCompute(w,"FillAllDepressions,FlowPath");

		# get the Flow Paths for the entire raster
		WatershedGetObject(w,"VectorFlowPath",flowpathFilename$,flowpathObjname$);
		flowpathInode = ObjectNumber(flowpathFilename$,flowpathObjname$,"VECTOR");

		CreateTempVector(VECFLOW);
		tempfilename$ = GetObjectFileName(VECFLOW);
		tempinode = GetObjectNumber(VECFLOW);
		tempobjname$ = GetObjectName(tempfilename$,tempinode);

		tempinode = CopyObject(flowpathFilename$,flowpathInode,tempfilename$);

		tempfilename$ = GetObjectFileName(VECFLOW);
		tempobjname$ = GetObjectName(tempfilename$,tempinode);
		CloseVector(VECFLOW);

		OpenVector(VECFLOW2,tempfilename$,tempobjname$);

		firstpass = 1;
		haslayers = 0;
		numpts = 1;

		# read and parse into memory the XML text describing the dialog; return an error code
		#  if there are syntax errors in the dialog specification.

		err = doc.Parse(
		'<?xml version="1.0"?>
			<root>
				<dialog id="dlgform" title="Flow Path and Buffer Zone" OnApply="OnApply()" OnOK="OnApply()">
					<book>
						<page Name="Controls">
							<pane Orientation="horizontal">
								<pushbutton Name="Save" Icon="FILE_SAVE" ToolTip="Save Output Layers..." OnPressed="DoSave()"/>
								<pushbutton Name="Remove" Icon="CONTROL_SUBTRACT_CYAN" ToolTip="Remove Output Layers" OnPressed="cbDoRemove()"/>
								<pushbutton Name="Number of Seedpoints..." OnPressed="DoSet()"/>
							</pane>
							<pane Orientation="vertical">
								<togglebutton id="btnSnap"		Name="Move Seed Point to Flow Path"	Selected="false"/>
								<togglebutton id="btnFlow"		Name="Compute Flow Path" 				Selected="true"/>
								<togglebutton id="btnBasin"	Name="Compute Upstream Basin" 		Selected="true"/>
								<togglebutton id="btnBuffer"	Name="Compute Buffer Zone" 			Selected="false"/>
							</pane>
							<pane Orientation="horizontal">
								<label>Buffer Distance: </label>
								<editnumber id="buffDist" Width ="5" Default="100" Precision="0" MinVal="0"/> 
							</pane>
						</page>
						<page Name="Colors" Orientation ="vertical">
							<pane Orientation ="horizontal">
								<colorbutton id="fcolor" OnChangeColor="OnChangefcolor()"/>
								<label>  Flow path color</label>
							</pane>
							<pane Orientation = "horizontal">
								<colorbutton id="bacolor" OnChangeColor="OnChangebacolor()"/>
								<label>  Basin color</label>
							</pane>
							<pane Orientation = "horizontal">
								<colorbutton id="bucolor" OnChangeColor="OnChangebucolor()"/>
								<label>  Buffer zone color</label>
							</pane>
							<pane Orientation = "horizontal">
								<colorbutton id="bocolor" OnChangeColor="OnChangebocolor()"/>
								<label>  Extents box color</label>
							</pane>
						</page>
					</book>
				</dialog>
			</root>' );

		if (err < 0 ) {		# pop up a dialog to report XML syntax errors
			PopupError(err);
			Exit();
			}

		# get the dialog element from the parsed XML structure and show error
		# message if the dialog element can't be found 
		dlgnode = doc.GetElementByID("dlgform");
		if (dlgnode == 0) {
			PopupMessage("Could not find dialog node in XML document");
			Exit();
			}

		# set the XML dialog element as the source for the GUI_DLG class instance
		# we are using for the main dialog window, and open as a modeless dialog
		dlgform.SetXMLNode(dlgnode);
		dlgform.CreateModeless();

		# Assign initial colors to color buttons on dialog
		fcolorbtn = dlgform.GetCtrlByID("fcolor");
		fcolorbtn.SetColor(fcolor);
		bacolorbtn = dlgform.GetCtrlByID("bacolor");
		bacolorbtn.SetColor(bacolor);
		bucolorbtn = dlgform.GetCtrlByID("bucolor");
		bucolorbtn.SetColor(bucolor);
		bocolorbtn = dlgform.GetCtrlByID("bocolor");
		bocolorbtn.SetColor(bocolor);

	StatusStop();


	}	# end of OnInitialize

# procedure to move seed point(s) to nearest flow path(s) before computing
# new watershed vectors
proc DoSnapSeed () {
	class VECTOR tempflowvector, TempFlowBuffer;
	class VECTOR stub;
	numeric linenumber;
	numeric a;
	numeric b;
	numeric returndistance;
	numeric tempx;
	numeric tempy;
	array tempseedx[1];
	array tempseedy[1];

	CreateTempVector(stub,"VectorToolkit");
	VectorToolkitInit(stub);
	tempseedx[1] = seedx[i];
	tempseedy[1] = seedy[i];
	StatusStart();
		WatershedComputeElements(w,tempseedx,tempseedy,1,"FlowPath");
	StatusStop();

	WatershedGetObject(w,"VectorUserFlowPath",userflowpathFilename$,userflowpathObjname$);
	OpenVector(tempflowvector,userflowpathFilename$,userflowpathObjname$);
	CreateTempVector(TempFlowBuffer);
	TempFlowBuffer = VectorToBufferZone(tempflowvector,"line",1,"meters");

	stub = VectorExtract(TempFlowBuffer,VECFLOW2,"InsideClip");

	# if this vector has no lines then the user defined flowpath runs straight off DEM
	# and doesn't connect with the flowpath so skip these calculations, thus leaving
	# the seedpoint where it was originally
	if (NumVectorLines(stub) > 0)	{
		string stubfilename$;
		string stubobjname$;
		numeric stubinode;

		stubfilename$ = GetObjectFileName(stub);
		stubinode = GetObjectNumber(stub);
		stubobjname$ = GetObjectName(stubfilename$,stubinode);

		class VECTOR stub2;
		CreateTempVector(stub2);
		stubfilename$ = GetObjectFileName(stub);
		stubinode = GetObjectNumber(stub);
		stubobjname$ = GetObjectName(stubfilename$,stubinode);
		CloseVector(stub);
		OpenVector(stub2,stubfilename$,stubobjname$,"VectorToolkit");

		pt.x = xhold[i];
		pt.y = yhold[i];
		pt = TransPoint2D(pt,ViewGetTransLayerToScreen(View,DEMLayer,1));
		pt = TransPoint2D(pt,ViewGetTransLayerToView(View,DEMLayer));
		pt = TransPoint2D(pt,ViewGetTransMapToView(View,DEMLayer.projection,1));

		MapToObject(GetLastUsedGeorefObject(stub2), pt.x, pt.y, stub2, tempx, tempy);
		linenumber = FindClosestLine(stub2,pt.x,pt.y,GetLastUsedGeorefObject(stub2),9999999.9,returndistance);

		ClosestPointOnLine(stub2,linenumber,tempx,tempy,a,b);
		ObjectToMap(stub2,a,b,GetLastUsedGeorefObject(stub),tempx,tempy);
		MapToObject(GetLastUsedGeorefObject(DEM),tempx,tempy,DEM,a,b);

		seedx[i] = a;
		seedy[i] = b;
		}  
	} # End of DoSnapSeed()

# compute and display flowpath,buffer and buffer zone if chosen by user 
proc DoFlowPath() {

	StatusStart();
	# compute vector flow paths originating at seed point location.
	# This step requires the previous computation of the depressionless DEM

	#don't draw view until we are done
	View.DisableRedraw = 1;

	#only calculate what we have to
	local btnFlowSet;
	local btnBasinSet;
	local btnBufferSet;

	class GUI_CTRL_TOGGLEBUTTON btnFlow, btnBasin, btnBuffer;		# this method works!
	btnFlow = dlgform.GetCtrlByID("btnFlow");
	btnBasin = dlgform.GetCtrlByID("btnBasin");
	btnBuffer = dlgform.GetCtrlByID("btnBuffer");

	btnFlowSet = btnFlow.GetValue();
	btnBasinSet = btnBasin.GetValue();
	btnBufferSet = btnBuffer.GetValue(); 

	########## Popup message for testing data retrieval from  dialog
	# PopupMessage( sprintf("Flow= %s, Basin= %s, Buffer = %s",btnFlowSet$,btnBasinSet$,btnBufferSet$) )

	if ((btnFlowSet == 0) and (btnBufferSet == 0) and (btnBasinSet == 0)) {
		return;
	}

	local string wsopt$;
	wsopt$ = "";

	if ( (btnFlowSet == 1) or (btnBufferSet ==1)) then wsopt$ = "FlowPath";

	if (btnBasinSet == 1) {
		if (wsopt$ != "") then wsopt$ = wsopt$ + ",";
		wsopt$ = wsopt$ + "Basin";
		}

	WatershedComputeElements(w,seedx,seedy,numpts,wsopt$);

	# if ((btnFlowSet == 1) or (btnBufferSet == 1) and (btnBasinSet == 1)) {
	# 	WatershedComputeElements(w,seedx,seedy,numpts,"FlowPath,Basin");
	# }
	# if ((btnBasinSet == 1) and (btnBufferSet == 0) and (btnFlowSet == 0)){
	#	WatershedComputeElements(w,seedx,seedy,numpts,"Basin");
	#	}
	# if (btnBasinSet == 0) {
	#	WatershedComputeElements(w,seedx,seedy,numpts,"FlowPath");
	# }

	if  ((btnFlowSet == 1) or (btnBufferSet == 1)) {
	WatershedGetObject(w,"VectorUserFlowPath",userflowpathFilename$,userflowpathObjname$);
	OpenVector(VectIn,userflowpathFilename$,userflowpathObjname$);
	}

	if (btnFlowSet == 1) { # had to calculate it for buffer now add it if they want it
		VecFlow = GroupQuickAddVectorVar(Group,VectIn);
		#change the displayed color according to user (previous) choice
		VecFlow.Line.NormalStyle.Color.red = fcolor.red;
		VecFlow.Line.NormalStyle.Color.green = fcolor.green;
		VecFlow.Line.NormalStyle.Color.blue = fcolor.blue;
	}

	# Compute Buffer zone around flow path
	if (btnBufferSet == 1) {
		class VECTOR Buffer, TempBuffer;
		class GUI_CTRL_EDIT_NUMBER buffDist;
		buffDist = dlgform.GetCtrlByID("buffDist");

		CreateTempVector(Buffer);
		CreateTempVector(TempBuffer);
		TempBuffer = VectorToBufferZone(VectIn,"line",buffDist.GetValueNum(),"meters");
		Buffer = VectorExtract(VecBoundary,TempBuffer,"InsideClip");
		VecBuf = GroupQuickAddVectorVar(Group,Buffer);
		VecBuf.Line.NormalStyle.Color.red = bucolor.red;
		VecBuf.Line.NormalStyle.Color.green = bucolor.green;
		VecBuf.Line.NormalStyle.Color.blue = bucolor.blue;
		}

	# Display basin if selected
	if (btnBasinSet == 1) {
		class VECTOR BasinVector;
		WatershedGetObject(w,"VectorUserBasin",userBasinFilename$,userBasinObjname$);
		OpenVector(BasinVector,userBasinFilename$,userBasinObjname$);
		BasinLayer = GroupQuickAddVectorVar(Group,BasinVector);
		BasinLayer.Poly.Select.Mode = "None";
		BasinLayer.Line.NormalStyle.Color.red = bacolor.red;
		BasinLayer.Line.NormalStyle.Color.green = bacolor.green;
		BasinLayer.Line.NormalStyle.Color.blue = bacolor.blue;
	}

	View.DisableRedraw = 0;
	ViewRedrawIfNeeded(View);
	haslayers = 1;

	StatusStop();

	}  # end of DoFlowPath

# Called when tool is to be destroyed, will not be called if tool was never activated. 
# If the tool implements a dialog it should be destroyed here. 
#don't destroy added layers here since they are already destroyed before this gets called
func OnDestroy () {
	WatershedClose(w);
	}  # end of OnDestroy 
 
# Called when tool is activated. 
# If the tool implements a dialog it should be "managed" (displayed) here. 
func OnActivate () { 

	StatusStart();

	if (!firstpass) {
		local numeric answer;
		answer = PopupYesNo("Keep Same Input DEM?");
		if (!answer) {
			CloseRaster(DEM);
			if (Group.FirstLayer.Type == "Raster") {
				DispGetRasterFromLayer(DEM,Group.FirstLayer);
				DEMLayer = Group.FirstLayer;
				}
		else {
			PopupString("First Layer must be a raster object for Watershed Toolscript");
			WaitForExit();
			}

		demFilename$ = GetObjectFileName(DEM);
		demInode = GetObjectNumber(DEM);
		demObjname$ = GetObjectName(demFilename$,demInode);

		#Initialize watershed object (assigns object handle)
		w = WatershedInit(demFilename$,demObjname$);

		#Fill all depressions in DEM and compute watersheds.
		#a depressionless version of the DEM is automatically created
		# as a temporary internal object associated with watershed handle w
		WatershedCompute(w,"FillAllDepressions,FlowPath");

		#get the Flow Paths for the entire raster
		WatershedGetObject(w,"VectorFlowPath",flowpathFilename$,flowpathObjname$);
		flowpathInode = ObjectNumber(flowpathFilename$,flowpathObjname$,"VECTOR");

		CreateTempVector(VECFLOW);
		tempfilename$ = GetObjectFileName(VECFLOW);
		tempinode = GetObjectNumber(VECFLOW);
		tempobjname$ = GetObjectName(tempfilename$,tempinode);

		tempinode = CopyObject(flowpathFilename$,flowpathInode,tempfilename$);

		tempfilename$ = GetObjectFileName(VECFLOW);
		tempobjname$ = GetObjectName(tempfilename$,tempinode);
		CloseVector(VECFLOW);

		OpenVector(VECFLOW2,tempfilename$,tempobjname$);
		}
	}

	# draw vector box around DEM so can show and clip buffer zone to it
	CreateTempVector(VecBoundary,"VectorToolkit");
	local class GEOREF g = GetLastUsedGeorefObject(DEM);
	CreateImpliedGeoref(VecBoundary, g.CoordRefSys);
	VectorToolkitInit(VecBoundary);
	GetObjectExtents(DEM,xMin,yMin,xMax,yMax,GetLastUsedGeorefObject(DEM));
	xPoints[1] = xMin;
	yPoints[1] = yMin;
	xPoints[2] = xMax;
	yPoints[2] = yMin;
	xPoints[3] = xMax;
	yPoints[3] = yMax;
	xPoints[4] = xMin;
	yPoints[4] = yMax;
	xPoints[5] = xMin;
	yPoints[5] = yMin;
	VectorAddLine(VecBoundary, 5, xPoints, yPoints);

	CloseVector(VecBoundary);

	View.DisableRedraw = 1;
	BoundaryLayer.Poly.Select.Mode = "None";
	BoundaryLayer = GroupQuickAddVectorVar(Group,VecBoundary);
	BoundaryLayer.IgnoreExtents = 1;
	BoundaryLayer.Line.NormalStyle.Color.red = bocolor.red;
	BoundaryLayer.Line.NormalStyle.Color.green = bocolor.green;
	BoundaryLayer.Line.NormalStyle.Color.blue = bocolor.blue;

	View.DisableRedraw = 0;
	ViewRedrawIfNeeded(View);

	# set i 
	i = 1;

	dlgform.Open();
	setDefaultWhenClose = true;

	StatusStop();

	} # end of OnActivate
 
# Called when tool is deactivated (usually when switching to another tool). 
# If the tool implements a dialog it should be "unmanaged" (hidden) here. 
func OnDeactivate () { 

	DoRemove();
	View.DisableRedraw = 1;
	BoundaryLayer = LayerDestroy(BoundaryLayer);
	View.DisableRedraw = 0;
	ViewRedrawIfNeeded(View);

	firstpass = 0;
	setDefaultWhenClose = false;
	dlgform.Close(0);
	}  # end of OnDeactivate 

# Called when Apply button on dialog is pressed.
proc OnApply () {
	DoRemove();

	if (i <= numpts) {

		# make sure seed points are within bounds of raster
		if (seedx[i] > (DEM.$Info.NumCols-1))
			seedx[i] = (DEM.$Info.NumCols-1);
		if (seedx[i] < 0)
			seedx[i] = 0;

		if (seedy[i] > (DEM.$Info.NumLins-1))
			seedy[i] = (DEM.$Info.NumLins-1);
		if (seedy[i] < 0)
			seedy[i] = 0;

		#if user wants to move seedpoint to flowpath
		if (dlgform.GetCtrlValueNum("btnSnap") == 1) {
			DoSnapSeed();
			}
		i = i + 1;
		}

	if (i > numpts) {
		DoFlowPath();
		i = 1;
		}
	}

# Called when user releases 'left' pointer/mouse button.
func OnLeftButtonPress() {

	DoRemove();

	if (i <= numpts) {
		pt.x = PointerX;
		pt.y = PointerY;
		xhold[i] = PointerX;
		yhold[i] = PointerY;

		pt = TransPoint2D(pt,ViewGetTransLayerToScreen(View, DEMLayer, 1));

		seedx[i] = pt.x;
		seedy[i] = pt.y;

		# make sure seed points are within bounds of raster
		if (seedx[i] > (DEM.$Info.NumCols-1))
			seedx[i] = (DEM.$Info.NumCols-1);
		if (seedx[i] < 0)
			seedx[i] = 0;

		if (seedy[i] > (DEM.$Info.NumLins-1))
			seedy[i] = (DEM.$Info.NumLins-1);
		if (seedy[i] < 0)
			seedy[i] = 0;

		#if user wants to move seedpoint to flowpath
		if (dlgform.GetCtrlValueNum("btnSnap") == 1) {
			DoSnapSeed();
			}
		i = i + 1;
		}

	if (i > numpts) {
		DoFlowPath();
		i = 1;
		}
	} # end of OnLeftButtonPress()