From 226529a97bd6445f92927395b73a513bd9d0a454 2010-08-09 20:03:39
From: epatters <epatters@enthought.com>
Date: 2010-08-09 20:03:39
Subject: [PATCH] * ConsoleWidget now has better support for non-GUI tab completion. Multiple matches are formatted into columns.
* Tab width can now be set at runtime rather than only during initialization.
* Added external module columnize.py

---

diff --git a/IPython/external/columnize.py b/IPython/external/columnize.py
new file mode 100644
index 0000000..fc70433
--- /dev/null
+++ b/IPython/external/columnize.py
@@ -0,0 +1,160 @@
+"""Return compact set of columns as a string with newlines for an
+array of strings.
+
+Adapted from the routine of the same name inside cmd.py
+
+Author: Rocky Bernstein.
+License: MIT Open Source License.
+"""
+
+import types
+
+def columnize(array, displaywidth=80, colsep = '  ', 
+              arrange_vertical=True, ljust=True, lineprefix=''):
+    """Return a list of strings as a compact set of columns arranged 
+    horizontally or vertically.
+
+    For example, for a line width of 4 characters (arranged vertically):
+        ['1', '2,', '3', '4'] => '1  3\n2  4\n'
+   
+    or arranged horizontally:
+        ['1', '2,', '3', '4'] => '1  2\n3  4\n'
+        
+    Each column is only as wide as necessary.  By default, columns are
+    separated by two spaces - one was not legible enough. Set "colsep"
+    to adjust the string separate columns. Set `displaywidth' to set
+    the line width. 
+
+    Normally, consecutive items go down from the top to bottom from
+    the left-most column to the right-most. If "arrange_vertical" is
+    set false, consecutive items will go across, left to right, top to
+    bottom."""
+    if not isinstance(array, list) and not isinstance(array, tuple): 
+        raise TypeError, (
+            'array needs to be an instance of a list or a tuple')
+
+    array = [str(i) for i in array]
+
+    # Some degenerate cases
+    size = len(array)
+    if 0 == size: 
+        return "<empty>\n"
+    elif size == 1:
+        return '%s\n' % str(array[0])
+
+    displaywidth = max(4, displaywidth - len(lineprefix))
+    if arrange_vertical:
+        array_index = lambda nrows, row, col: nrows*col + row
+        # Try every row count from 1 upwards
+        for nrows in range(1, size):
+            ncols = (size+nrows-1) // nrows
+            colwidths = []
+            totwidth = -len(colsep)
+            for col in range(ncols):
+                # get max column width for this column
+                colwidth = 0
+                for row in range(nrows):
+                    i = array_index(nrows, row, col)
+                    if i >= size: break
+                    x = array[i]
+                    colwidth = max(colwidth, len(x))
+                    pass
+                colwidths.append(colwidth)
+                totwidth += colwidth + len(colsep)
+                if totwidth > displaywidth: 
+                    break
+                pass
+            if totwidth <= displaywidth: 
+                break
+            pass
+        # The smallest number of rows computed and the
+        # max widths for each column has been obtained.
+        # Now we just have to format each of the
+        # rows.
+        s = ''
+        for row in range(nrows):
+            texts = []
+            for col in range(ncols):
+                i = row + nrows*col
+                if i >= size:
+                    x = ""
+                else:
+                    x = array[i]
+                texts.append(x)
+            while texts and not texts[-1]:
+                del texts[-1]
+            for col in range(len(texts)):
+                if ljust:
+                    texts[col] = texts[col].ljust(colwidths[col])
+                else:
+                    texts[col] = texts[col].rjust(colwidths[col])
+                    pass
+                pass
+            s += "%s%s\n" % (lineprefix, str(colsep.join(texts)))
+            pass
+        return s
+    else:
+        array_index = lambda nrows, row, col: ncols*(row-1) + col
+        # Try every column count from size downwards
+        prev_colwidths = []
+        colwidths = []
+        for ncols in range(size, 0, -1):
+            # Try every row count from 1 upwards
+            min_rows = (size+ncols-1) // ncols
+            for nrows in range(min_rows, size):
+                rounded_size = nrows * ncols
+                colwidths = []
+                totwidth  = -len(colsep)
+                for col in range(ncols):
+                    # get max column width for this column
+                    colwidth  = 0
+                    for row in range(1, nrows+1):
+                        i = array_index(nrows, row, col)
+                        if i >= rounded_size: break
+                        elif i < size:
+                            x = array[i]
+                            colwidth = max(colwidth, len(x))
+                            pass
+                        pass
+                    colwidths.append(colwidth)
+                    totwidth += colwidth + len(colsep)
+                    if totwidth >= displaywidth: 
+                        break
+                    pass
+                if totwidth <= displaywidth and i >= rounded_size-1:
+                    # Found the right nrows and ncols
+                    nrows  = row
+                    break
+                elif totwidth >= displaywidth:
+                    # Need to reduce ncols
+                    break
+                pass
+            if totwidth <= displaywidth and i >= rounded_size-1:
+                break
+            pass
+        # The smallest number of rows computed and the
+        # max widths for each column has been obtained.
+        # Now we just have to format each of the
+        # rows.
+        s = ''
+        for row in range(1, nrows+1):
+            texts = []
+            for col in range(ncols):
+                i = array_index(nrows, row, col)
+                if i >= size:
+                    break
+                else: x = array[i]
+                texts.append(x)
+                pass
+            for col in range(len(texts)):
+                if ljust:
+                    texts[col] = texts[col].ljust(colwidths[col])
+                else:
+                    texts[col] = texts[col].rjust(colwidths[col])
+                    pass
+                pass
+            s += "%s%s\n" % (lineprefix, str(colsep.join(texts)))
+            pass
+        return s
+    pass
+
diff --git a/IPython/frontend/qt/console/console_widget.py b/IPython/frontend/qt/console/console_widget.py
index a5bba3b..2745443 100644
--- a/IPython/frontend/qt/console/console_widget.py
+++ b/IPython/frontend/qt/console/console_widget.py
@@ -5,6 +5,7 @@ import sys
 from PyQt4 import QtCore, QtGui
 
 # Local imports
+from IPython.external.columnize import columnize
 from ansi_code_processor import QtAnsiCodeProcessor
 from completion_widget import CompletionWidget
 
@@ -29,9 +30,6 @@ class ConsoleWidget(QtGui.QPlainTextEdit):
     # priority (when it has focus) over, e.g., window-level menu shortcuts.
     override_shortcuts = False
 
-    # The number of spaces to show for a tab character.
-    tab_width = 8
-
     # Protected class variables.
     _ctrl_down_remap = { QtCore.Qt.Key_B : QtCore.Qt.Key_Left,
                          QtCore.Qt.Key_F : QtCore.Qt.Key_Right,
@@ -62,6 +60,7 @@ class ConsoleWidget(QtGui.QPlainTextEdit):
         self._prompt_pos = 0
         self._reading = False
         self._reading_callback = None
+        self._tab_width = 8
 
         # Set a monospaced font.
         self.reset_font()
@@ -113,7 +112,7 @@ class ConsoleWidget(QtGui.QPlainTextEdit):
         self._context_menu.exec_(event.globalPos())
 
     def dragMoveEvent(self, event):
-        """ Reimplemented to disable dropping text.
+        """ Reimplemented to disable moving text by drag and drop.
         """
         event.ignore()
 
@@ -467,6 +466,21 @@ class ConsoleWidget(QtGui.QPlainTextEdit):
         font = QtGui.QFont(name, QtGui.qApp.font().pointSize())
         font.setStyleHint(QtGui.QFont.TypeWriter)
         self._set_font(font)
+
+    def _get_tab_width(self):
+        """ The width (in terms of space characters) for tab characters.
+        """
+        return self._tab_width
+
+    def _set_tab_width(self, tab_width):
+        """ Sets the width (in terms of space characters) for tab characters.
+        """
+        font_metrics = QtGui.QFontMetrics(self.font)
+        self.setTabStopWidth(tab_width * font_metrics.width(' '))
+
+        self._tab_width = tab_width
+
+    tab_width = property(_get_tab_width, _set_tab_width)
         
     #---------------------------------------------------------------------------
     # 'ConsoleWidget' abstract interface
@@ -563,9 +577,34 @@ class ConsoleWidget(QtGui.QPlainTextEdit):
             if self.gui_completion:
                 self._completion_widget.show_items(cursor, items) 
             else:
-                text = '\n'.join(items) + '\n'
+                text = self.format_as_columns(items)
                 self._append_plain_text_keeping_prompt(text)
 
+    def format_as_columns(self, items, separator='  ', vertical=True):
+        """ Transform a list of strings into a single string with columns.
+
+        Parameters
+        ----------
+        items : sequence [str]
+            The strings to process.
+
+        separator : str, optional [default is two spaces]
+            The string that separates columns.
+
+        vertical: bool, optional [default True] 
+            If set, consecutive items will be arranged from top to bottom, then
+            from left to right. Otherwise, consecutive items will be aranged
+            from left to right, then from top to bottom.
+
+        Returns
+        -------
+        The formatted string.
+        """
+        font_metrics = QtGui.QFontMetrics(self.font)
+        width = self.width() / font_metrics.width(' ')
+        return columnize(items, displaywidth=width, 
+                         colsep=separator, arrange_vertical=vertical)
+
     def _get_block_plain_text(self, block):
         """ Given a QTextBlock, return its unformatted text.
         """
diff --git a/IPython/frontend/qt/console/frontend_widget.py b/IPython/frontend/qt/console/frontend_widget.py
index f94721d..c3ae3ea 100644
--- a/IPython/frontend/qt/console/frontend_widget.py
+++ b/IPython/frontend/qt/console/frontend_widget.py
@@ -63,10 +63,7 @@ class FrontendHighlighter(PygmentsHighlighter):
 class FrontendWidget(HistoryConsoleWidget):
     """ A Qt frontend for a generic Python kernel.
     """
-
-    # ConsoleWidget interface.
-    tab_width = 4
-    
+   
     # Emitted when an 'execute_reply' is received from the kernel.
     executed = QtCore.pyqtSignal(object)
 
@@ -86,6 +83,7 @@ class FrontendWidget(HistoryConsoleWidget):
         self._kernel_manager = None
 
         # Configure the ConsoleWidget.
+        self.tab_width = 4
         self._set_continuation_prompt('... ')
 
         self.document().contentsChange.connect(self._document_contents_change)
@@ -121,7 +119,7 @@ class FrontendWidget(HistoryConsoleWidget):
             prompt created. When triggered by an Enter/Return key press,
             'interactive' is True; otherwise, it is False.
         """
-        complete = self._input_splitter.push(source.replace('\t', '    '))
+        complete = self._input_splitter.push(source.expandtabs(4))
         if interactive:
             complete = not self._input_splitter.push_accepts_more()
         return complete