Editorgadget

[spacebuddy]

With the EditorGadGet is it possible to find the line number and column the cursor is at?

I looked in the help file but could not find anything.

I would like my editor program to display the line number and column in real time.

[Danilo]

I looked in the help file but could not find anything.

If you meant the PB help, don't look any further. PB does not support 'advanced' things like that, you have to use the OS API's directly on all platforms.

[Shardik]

You will encounter two problems if trying to obtain the cursor's line and column number in an EditorGadget on MacOS X:

- You need to detect whenever the cursor changes its position in the EditorGadget. PureBasic currently won't detect this, so you have to establish a callback for the Cocoa method textViewDidChangeSelection:. This is an easy part.

- The underlying native control of the EditorGadget is the NSTextView. Inherited controls are NSText, NSView, NSResponder and NSObject. They (and their delegates) all don't offer the possibility to obtain the current cursor's line and column number although it's fairly easy and fast to obtain the current cursor's position index. If you want to obtain the cursor's line and column number from the cursor's position index, things become a little bit more complicated because you have to take word wrap into account. With word wrap disabled you can simply count the lind feeds and calculate the current line of the cursor. But with word wrap enabled you have to take into account the line feeds, the wrapping of lines without line feeds and the maximum number of visible characters per line at the current EditorGadget's width (and that on a word basis). Another problem would be that this approach would increasingly become slower with larger texts...

Therefore - and for the sake of simplicity - the following example demonstrates how to always display the current cursor's position index in the StatusBar (currently doesn't work in Unicode mode!):

Code: Select all

EnableExplicit

ImportC ""
  sel_registerName(MethodName.S)
  class_addMethod(Class.I, Selector.I, Implementation.I, Types.S)
EndImport

ProcedureC SelectionDidChangeCallback(Object.I, Selector.I, Notification.I)
  Protected Range.NSRange

  CocoaMessage(@Range, GadgetID(0), "selectedRange")
  StatusBarText(0, 0, "Cursor position: " + Str(Range\location),
    #PB_StatusBar_Center)
EndProcedure

Define AppDelegate.I = CocoaMessage(0, CocoaMessage(0, 0,
  "NSApplication sharedApplication"), "delegate")
Define DelegateClass.I = CocoaMessage(0, AppDelegate, "class")
Define Range.NSRange
Define Selector.I = sel_registerName("textViewDidChangeSelection:")

OpenWindow(0, 270, 100, 180, 100, "EditorGadget")
CreateStatusBar(0, WindowID(0))
AddStatusBarField(#PB_Ignore)
EditorGadget(0, 10, 10, 160, 60, #PB_Editor_WordWrap)
SetGadgetFont(0, LoadFont(0, "Monaco", 13))
SetGadgetText(0, "The quick brown fox jumps over the lazy dog.")
SetActiveGadget(0)

class_addMethod(DelegateClass, Selector, @SelectionDidChangeCallback(), "v@:@")
CocoaMessage(0, GadgetID(0), "setDelegate:", AppDelegate)

; ----- Set cursor in front of 1st character
CocoaMessage(0, GadgetID(0), "setSelectedRange:@", @Range)

Repeat
Until WaitWindowEvent() = #PB_Event_CloseWindow

[IdeasVacuum]

The ScintillaGadget is probably a better bet, (works really well on Windows OS) and has a rich set of functions.