Class: Win32::Clipboard

Inherits:
Object
  • Object
show all
Extended by:
Windows::Functions, Windows::Structs
Includes:
Windows::Constants, Windows::Functions, Windows::Structs
Defined in:
lib/win32/clipboard.rb

Overview

The Clipboard class encapsulates functions that relate to the MS Windows clipboard.

Direct Known Subclasses

HtmlClipboard

Constant Summary collapse

VERSION =

The version of this library

'0.6.1'
TEXT =

Text

1
OEMTEXT = 
7
UNICODETEXT = 
13
DIB =

Images

8
BITMAP = 
2
ENHMETAFILE =

Metafiles

14
HDROP =

Files

15

Constants included from Windows::Constants

Windows::Constants::CF_TEXT, Windows::Constants::GHND, Windows::Constants::GWL_USERDATA, Windows::Constants::GWL_WNDPROC, Windows::Constants::WM_CHANGECBCHAIN, Windows::Constants::WM_DRAWCLIPBOARD

Class Method Summary collapse

Class Method Details

.data(format = TEXT) ⇒ Object Also known as: get_data

Returns the data currently in the clipboard. If format is specified, it will attempt to retrieve the data in that format. The default is Clipboard::TEXT.

If there is no data in the clipboard, or data is available but the format doesn’t match the data, then an empty string is returned.

Examples:

# Get some plain text
Win32::Clipboard.data # => e.g. 'hello'

# Get a list of files copied from the Windows Explorer window
Win32::Clipboard.data(Clipboard::HDROP) # => ['foo.rb', 'bar.rb']

# Get a bitmap and write it to another file
File.open('bitmap_copy', 'wb'){ |fh|
   fh.write Win32::Clipboard.data(Clipboard::DIB)
}



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# File 'lib/win32/clipboard.rb', line 91

def self.data(format = TEXT)
  begin
    open

    if IsClipboardFormatAvailable(format)
      handle = GetClipboardData(format)

      case format
        when UNICODETEXT
          size = GlobalSize(handle)
          ptr  = GlobalLock(handle)
          clip_data = ptr.read_bytes(size).force_encoding('UTF-16LE').encode('UTF-8').strip
        when TEXT, OEMTEXT
          size = GlobalSize(handle)
          ptr  = GlobalLock(handle)

          clip_data = ptr.read_bytes(size).strip

          unless clip_data.ascii_only?
            clip_data.force_encoding('BINARY')
          end
        when HDROP
          clip_data = get_file_list(handle)
        when ENHMETAFILE
          clip_data = get_metafile_data(handle)
        when DIB, BITMAP
          clip_data = get_image_data(handle)
        else
          raise "format '#{format}' not supported"
      end
    else
      clip_data = ''
    end
  ensure
    close
  end

  clip_data
end

.empty ⇒ Object Also known as: clear

Empties the contents of the clipboard.



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# File 'lib/win32/clipboard.rb', line 44

def self.empty
  begin
    open
    unless EmptyClipboard()
      raise SystemCallError.new('EmptyClipboard', FFI.errno)
    end
  ensure
    close
  end
end

.format_available?(format) ⇒ Boolean

Returns whether or not format (an integer) is currently available.

Returns:

  • (Boolean) 


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# File 'lib/win32/clipboard.rb', line 67

def self.format_available?(format)
  IsClipboardFormatAvailable(format)
end

.format_name(format_num) ⇒ Object

Returns the corresponding name for the given format_num, or nil if it does not exist. You cannot specify any of the predefined clipboard formats (or nil is returned), only registered formats.



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# File 'lib/win32/clipboard.rb', line 215

def self.format_name(format_num)
  val = nil
  buf = FFI::MemoryPointer.new(:char, 80)

  begin
    open

    if GetClipboardFormatName(format_num, buf, buf.size) != 0
      val = buf.read_string
    end
  ensure
    close
  end

  val
end

.formats ⇒ Object

Returns a hash of all the current formats, with the format number as the key and the format name as the value for that key.

Example:

Win32::Clipboard.formats # => {1 => nil, 49335 => "HTML Format"}



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# File 'lib/win32/clipboard.rb', line 192

def self.formats
  formats = {}
  format = 0

  begin
    self.open
    while 0 != (format = EnumClipboardFormats(format))
      buf = FFI::MemoryPointer.new(:char, 80)
      GetClipboardFormatName(format, buf, buf.size)
      string = buf.read_string
      formats[format] = string.empty? ? nil : string
    end
  ensure
    self.close
  end

  formats
end

.notify_change(&block) ⇒ Object

Sets up a notification loop that will call the provided block whenever there’s a change to the clipboard.

Example:

Win32::Clipboard.notify_change{
   puts "There's been a change in the clipboard contents!"
}

– We skip the first notification because the very act of attaching the new window causes it to trigger once.



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# File 'lib/win32/clipboard.rb', line 267

def self.notify_change(&block)
  name   = 'ruby-clipboard-' + Time.now.to_s
  handle = CreateWindowEx(0, 'static', name, 0, 0, 0, 0, 0, 0, 0, 0, nil)

  @first_notify = true

  wnd_proc = FFI::Function.new(:uintptr_t, [:uintptr_t, :uint, :uintptr_t, :uintptr_t]) do |hwnd, umsg, wparam, lparam|
    case umsg
       when WM_DRAWCLIPBOARD
         yield unless @first_notify
         next_viewer = GetWindowLongPtr(hwnd, GWL_USERDATA)
         if next_viewer != 0
           PostMessage(next_viewer, umsg, wparam, lparam)
         end
         rv = 0
       when WM_CHANGECBCHAIN
         yield unless @first_notify
         next_viewer = lparam if next_viewer == wparam
         if next_viewer != 0
           PostMessage(next_viewer, umsg, wparam, lparam)
         end
         rv = 0
       else
         rv = DefWindowProc(hwnd, umsg, wparam, lparam)
    end

    @first_notify = false

    rv
  end

  if SetWindowLongPtr(handle, GWL_WNDPROC, wnd_proc.address) == 0
    raise SystemCallError.new('SetWindowLongPtr', FFI.errno)
  end

  next_viewer = SetClipboardViewer(handle)

  if next_viewer.nil?
    raise SystemCallError.new('SetClipboardViewer', FFI.errno)
  end

  SetWindowLongPtr(handle, GWL_USERDATA, next_viewer)

  msg = FFI::MemoryPointer.new(:char, 100)

  while true
    while PeekMessage(msg, handle, 0, 0, 1)
      TranslateMessage(msg)
      DispatchMessage(msg)
    end
    sleep 0.1
  end
end

.num_formats ⇒ Object

Returns the number of different data formats currently on the clipboard.



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# File 'lib/win32/clipboard.rb', line 61

def self.num_formats
  CountClipboardFormats() || 0
end

.register_format(format) ⇒ Object

Registers the given format (a String) as a clipboard format, which can then be used as a valid clipboard format. Returns the integer value of the registered format.

If a registered format with the specified name already exists, a new format is not registered and the return value identifies the existing format. This enables more than one application to copy and paste data using the same registered clipboard format. Note that the format name comparison is case-insensitive.

Registered clipboard formats are identified by values in the range 0xC000 through 0xFFFF.



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# File 'lib/win32/clipboard.rb', line 245

def self.register_format(format)
  format_value = RegisterClipboardFormat(format)

  if format_value == 0
    raise SystemCallError.new('RegisterClipboardFormat', FFI.errno)
  end

  format_value
end

.set_data(clip_data, format = TEXT) ⇒ Object

Sets the clipboard contents to the data that you specify. You may optionally specify a clipboard format. The default is Clipboard::TEXT.

Example:

# Put the string 'hello' on the clipboard
Win32::Clipboard.set_data('hello')

# Put the image test.bmp on the clipboard
f = File.open("test.bmp", "rb")
str = f.read
Clipboard.set_data(str, Win32::Clipboard::DIB)



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# File 'lib/win32/clipboard.rb', line 148

def self.set_data(clip_data, format = TEXT)
  begin
    clear
    open

    # NULL terminate text or strip header of bitmap file
    case format
      when UNICODETEXT
        clip_data.encode!('UTF-16LE')
        clip_data << "\0".encode('UTF-16LE')
        buf = clip_data
        extra = 4
      when TEXT, OEMTEXT
        clip_data << "\0"
        buf = clip_data
        extra = 4
      when BITMAP, DIB
        buf = clip_data[14..clip_data.length] # sizeof(BITMAPFILEHEADER) = 14
        extra = 0
    end

    # Global Allocate a movable piece of memory.
    hmem = GlobalAlloc(GHND, buf.bytesize + extra)
    mptr = GlobalLock(hmem)

    mptr.write_bytes(buf, 0, buf.bytesize)

    # Set the new data
    if SetClipboardData(format, hmem) == 0
      raise SystemCallError.new('SetClipboardData', FFI.errno)
    end
  ensure
    GlobalFree(hmem)
    close
  end
end