CVEV 118/698 AutoCAD VBA Lecture 3 Prof. Mounir Mabsout Elsa Sulukdjian Walid El Asmar

For iterating through a selection set, the For-Each- Next loop structure may not be best at all times. For iterating through a selection set, the For-Each- Next loop structure may not be best at all times. Example: when selectively removing objects from the selection set. The For-Each-Next loop starts at the beginning of the list till the end of it and the removal of an item from the list inside the loop will cause the loop to skip one. 2 alternative ways of solving this problem: 2 alternative ways of solving this problem: – Using an array containing the object references to the items to be removed from the set. After the loop remove items with the RemoveItems method. – Remove items as found but within a While loop that starts at the back of the collection and working forward. Selection Set Collection Iterations

Object Removal from Selection Set – Example 1 Selection set filter 1: Array containing object references to items to be removed from selection set: Sub My_Filter1(SS As AcadSelectionSet, ET As Object) Dim Ents() As Object Dim Ents() As Object Dim Ent As Object Dim Ent As Object i = 0 i = 0 For Each Ent In SS For Each Ent In SS If Ent.EntityType <> ET.EntityType Then If Ent.EntityType <> ET.EntityType Then ReDim Preserve Ents(0 To i) ReDim Preserve Ents(0 To i) Set Ents(i) = Ent Set Ents(i) = Ent i = i + 1 i = i + 1 End If End If Next Ent Next Ent If i > 0 Then If i > 0 Then SS.RemoveItems (Ents) SS.RemoveItems (Ents) End If End If End Sub Note: “Preserve” maintains the values in the array as it is expanded while “ReDim” by itself will destroy the current contents of the array.

Object Removal from Selection Set – Example 2 Selection set filter 2: Removing items from a selection set using a While loop that starts at the back of the collection and working forward: Sub My_Filter2(SS As AcadSelectionSet, ET As Object) Dim Ent(0) As Object Dim Ent(0) As Object i = SS.Count i = SS.Count While (i > 0) While (i > 0) i = i - 1 i = i - 1 Set Ent(0) = SS.Item(i) Set Ent(0) = SS.Item(i) If Ent(0).EntityType <> ET.EntityType Then If Ent(0).EntityType <> ET.EntityType Then SS.RemoveItems (Ents) SS.RemoveItems (Ents) End If End If Wend Wend End Sub

Filtering the Selection Set For selection of specific entity objects in an application, working with subsets, I.e. Selection Sets, makes it easier. For selection of specific entity objects in an application, working with subsets, I.e. Selection Sets, makes it easier. To build a selection set of certain types of objects or objects that share specific property traits, you can use a filter. To build a selection set of certain types of objects or objects that share specific property traits, you can use a filter. A filter is a set of properties that the entity objects need to match in order to be included in the selection set (properties can be specific object types as well as ranges of values – ex: all circles with radii 1 and 2 drawing units). A filter is a set of properties that the entity objects need to match in order to be included in the selection set (properties can be specific object types as well as ranges of values – ex: all circles with radii 1 and 2 drawing units). In VBA, a filter is constructed as 2 arrays of variants containing information that consists of group codes and data values. In VBA, a filter is constructed as 2 arrays of variants containing information that consists of group codes and data values.

The Filter The 1 st array of the filter contains group codes only. The 1 st array of the filter contains group codes only. Group Codes: are integer values that indicate the type of data being referenced. The data itself resides in the 2 nd array. The index value links the 2 arrays (the 1 st value in the group codes array correspond with the 1 st value in the data array). Group Codes: are integer values that indicate the type of data being referenced. The data itself resides in the 2 nd array. The index value links the 2 arrays (the 1 st value in the group codes array correspond with the 1 st value in the data array). The 2 nd array contains the data elements associated with the group codes. The 2 nd array contains the data elements associated with the group codes. Data Elements: will be of different data types that correspond to the integer codes (ex: group code 2 will have a string, group code 10 will have a point). Data Elements: will be of different data types that correspond to the integer codes (ex: group code 2 will have a string, group code 10 will have a point). The 2 arrays MUST then be assigned to variant variables that are passed to the selection set function. The reason for using variants is to ease the transfer of information from BASIC to other environments. The 2 arrays MUST then be assigned to variant variables that are passed to the selection set function. The reason for using variants is to ease the transfer of information from BASIC to other environments.

Most Frequently Used Group Codes Group Code Data Contents 0 Object type string – LINE, ARC, or CIRCLE 1 String value in Text, Mtext 2 Object name string – used for Blocks & Tables 8 Layer name string 10 Primary point 11… Secondary points for text alignments, line endpoints,… 40 Arc and circle radius 62 Color number (integer) 67 Model/Paper space integer flag (value of 1 indicates the object is in paper space) -4 Grouping operator string or relational test (“<=“…)

Filter Selection Example Building a selection set from the entire drawing that will contain only CIRCLE entity objects with a radius of 5 drawing units: Building a selection set from the entire drawing that will contain only CIRCLE entity objects with a radius of 5 drawing units: Dim Ftyp(1) As Integer Dim Ftyp(1) As Integer Dim Fvar(1) As Variant Dim Filter1, Filter2 As Variant Ftyp(0) = 0: Fvar(0) = "CIRCLE" Ftyp(1) = 40: Fvar(1) = 5# Dim S1 As AcadSelectionSet Set S1 = ThisDrawing.SelectionSets.Add("S1") Filter1 = Ftyp 'Filter 1 is the FilterType Filter2 = Fvar 'Filter 2 is the FilterData S1.Select acSelectionSetAll,,, Filter1, Filter2 Arrays must be dimensioned to the proper size for the filters, I.e. if you ‘re using only 2 filter items, the array length should be exactly 2. Arrays must be dimensioned to the proper size for the filters, I.e. if you ‘re using only 2 filter items, the array length should be exactly 2.

Refining Filters – Numeric Tests Selection set containing all circles with a radius value less than or equal to 5 drawing units: Selection set containing all circles with a radius value less than or equal to 5 drawing units: Dim Ftyp1(2) As Integer Dim Fvar1(2) As Variant Dim Filter1, Filter2 As Variant Dim S1 As AcadSelectionSet Ftyp1(0) = 0: Fvar1(0) = "CIRCLE" Ftyp1(1) = -4: Fvar1(1) = "<=" Ftyp1(2) = 40: Fvar1(2) = 5# Set S1 = ThisDrawing.SelectionSets.Add("S1") Filter1 = Ftyp1 'Filter 1 is the FilterType Filter2 = Fvar1 'Filter 2 is the FilterData S1.Select acSelectionSetAll,,, Filter1, Filter2 The filter uses the (-4) group code. The comparison test is applied to the values that follow (here the radius value). The filter uses the (-4) group code. The comparison test is applied to the values that follow (here the radius value).

Numeric Relational Tests These tests are typically applied against real numbers found in entity object properties and they can also be applied for points: These tests are typically applied against real numbers found in entity object properties and they can also be applied for points: =Equal to <Less than >Greater than <=Less than or equal >= Greater than or equal != or /=Not equal to *Always-true returns true very time

Numeric Tests for Points Testing for objects that are located in the 1 st quadrant, I.e. having X and Y values >= 0: Testing for objects that are located in the 1 st quadrant, I.e. having X and Y values >= 0: Dim Pnt(0 To 2) As Double Dim Ftyp(1) As Integer: Dim Fvar(1) As Variant Dim Filter1, Filter2 As Variant Dim S1 As AcadSelectionSet Pnt(0) = 0#: Pnt(1) = 0#: Pnt(2) = 0# Ftyp(0) = -4: Fvar(0) = ">=,>=,*" Ftyp(1) = 10: Fval(1) = Pnt Filter1 = Ftyp 'Filter 1 is the FilterType Filter2 = Fval 'Filter 2 is the FilterData Set S1 = ThisDrawing.SelectionSets.Add("S1") S1.Select acSelectionSetAll,,, Filter1, Filter2

What’s Next More Objects More Objects More Methods More Methods