Auto Complete Problem

[RAKESHTATI]

I AM DOING PROJECT IN VB 6.0 AND USING RICHTEXTBOX
WHEN WE Type in “vo” IN RICHTEXTBOX and press “Ctrl + Enter”. The word “void” must be compeleted.LIKE THAT I HAVE TO DO SAME FOR ALL KEYWORDS CAN ANYONE SUGGEST

[leinad31]

You will have to store the words being looked up somewhere (vo could have been vocabulary or some other word)... you could return a subset of those words in a floating listbox (your other thread) for word completion... if only one word matches then complete the word.

[RAKESHTATI]

instead of all words,we need auto completion for only keywords.so,"for example,if we type v and press ctrl+enter,then void should be completed.otherwise we can go on with our word.no need of auto completion then"is there any possibility for this without use of listbox

[leinad31]

exactly, how will the computer know that void is one of the possible words when competed? where does the list of words that will be autocompleted reside?

[iPrank]

As leinad31 posted, you'll need to store the list of keywords somewhere and paste them in the RTB when matching word found.

If you don't want to show a floating listbox, then there is a problem. If user types very few letters then how will you decide which one to paste ?

Run the code below.
there are 3 keywords that starts wih "d" - double, default and do.
But if user just types "d" and Ctrl+Enter, the searching code will always pickup the first match ("double").
Similarly, if you type "do", then it can't decide between "double" and "do".
So, give the user a floating listbox like VB IDE (similar to the code posted in your other thread) to choose form.

' add a RichTextBox in a form and paste this code
Option Explicit
Private Declare Function LockWindowUpdate Lib "user32" ( _
   ByVal hwndLock As Long) As Long
 
Private Declare Function SendMessage Lib "user32.dll" Alias "SendMessageA" ( _
   ByVal hwnd As Long, _
   ByVal wMsg As Long, _
   ByVal wParam As Long, _
   ByRef lParam As Any) As Long
   
Private Const EM_LINEINDEX As Long = &HBB
Private KeyWords() As String
 
Private Sub Form_Load()
    KeyWords = Split("auto,const,double,float,int,short,struct,unsigned,break,continue,else,for,long,signed,switch,case,default,enum,void,goto,register,sizeof,typedef,volatile,char,do,extern,if,return,static,union,while", ",")
End Sub
 
Private Sub RichTextBox1_KeyDown(KeyCode As Integer, Shift As Integer)
    Dim CtrlDown As Boolean
    Dim LastSpace As Long
    Dim FindString As String
    Dim NewString As String
    Dim LineStart As Long
    CtrlDown = (Shift And vbCtrlMask) > 0
    If CtrlDown And KeyCode = 13 Then
        If RichTextBox1.SelStart > 0 Then
            ' get first character of line -->
            LineStart = SendMessage(RichTextBox1.hwnd, EM_LINEINDEX, RichTextBox1.GetLineFromChar(RichTextBox1.SelStart), 0&)
            If LineStart = RichTextBox1.SelStart - 1 Then
                LastSpace = LineStart
            Else
                ' YOU NEED TO ADD CHECK FOR MORE TERMINAL CHARACTERS HERE -->
                LastSpace = InStrRev(RichTextBox1.Text, " ", RichTextBox1.SelStart)
            End If
            If LastSpace >= 0 Then
                FindString = Mid$(RichTextBox1.Text, LastSpace + 1, RichTextBox1.SelStart - LastSpace)
                If FindString <> "" Then
                    NewString = GetAutoCompleteText(FindString)
                    If NewString <> "" Then
                        LockWindowUpdate RichTextBox1.hwnd
                        RichTextBox1.SelStart = LastSpace
                        RichTextBox1.SelLength = Len(FindString)
                        RichTextBox1.SelText = NewString
                        LockWindowUpdate 0
                    End If
                End If
            End If
        End If
        KeyCode = 0
    End If
End Sub
 
Private Function GetAutoCompleteText(FindString As String) As String
    Dim i As Long
    For i = 0 To UBound(KeyWords)
        If Left$(KeyWords(i), Len(FindString)) = FindString Then
            GetAutoCompleteText = KeyWords(i)
            Exit Function
        End If
    Next
    GetAutoCompleteText = ""
End Function

[iPrank]

If you decide to use a ListBox, see this thread (uses LB_FINDSTRING message).

There is another Message, LB_FINDSTRINGEXACT, that will give you exact match.

My idea is, (like VB)
1. Load the list of keywords in the listbox. keep it in sorted order and keep it hidden.
2. Detect Ctrl+Enter and get text to search (using above code)
3. Search the listview using LB_FINDSTRINGEXACT.
4. If match found, paste the string in RTB.
5. If exact match not found, show the listbox like your other thread.
6. find/highlight the matching text using LB_FINDSTRING

[RAKESHTATI]

your code written in post 5 is working properly.but we have encountered a small problem.if we want to perform auto complete at the starting of line i.e (no space is prezent in that line yet),then that code can't work as we are checking for " " in richtextbox using instrrev.

[iPrank]

your code written in post 5 is working properly.but we have encountered a small problem.if we want to perform auto complete at the starting of line i.e (no space is prezent in that line yet),then that code can't work as we are checking for " " in richtextbox using instrrev.

Yes. That code is not complete.

In addition to space (" "), you'll need to add check for puntuation marks, vbNewLine, first-word-of-document etc 'word-termination-characters'.

[RAKESHTATI]

GUD MRNG.
if we check for the first word of the document,how can we get autocomplete when we press ctrl+enter after "in" instead of after "i".
how can we overcome this?

[iPrank]

I've edited my previous code. try this time. Solves first-char-of-document problem.

The "in"/"i" problem is causing because we are only searching for space (" ").
Add search for vbLf, then it will not happen,

[RAKESHTATI]

ok thanks a lot mr.iprank it is working as we need