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<h1 ALIGN="CENTER">Pmw.HistoryText</h1>
<center><IMG SRC=HistoryText.gif ALT="" WIDTH=551 HEIGHT=142></center>
<dl>
<dt> <h3>Name</h3></dt><dd>
<p>Pmw.HistoryText() -
text widget with a course-grained form of history
</p>
</dd>
<dt> <h3>Inherits</h3></dt><dd>
<a href="ScrolledText.html">Pmw.ScrolledText</a><br>
</dd>
<dt> <h3>Description</h3></dt><dd>
<p>
A history text is a scrolled text widget with added functionality
to maintain a history of each screen and allow editing of prior
screens. Here, <em>screen</em> refers to the entire contents of the text
widget. This widget does not support a fine-grained history of
every change made to the text.</p>
<p> Together with a few buttons and a scrolled text to display the
results, a history text can be used as the query-entry part of a
simple interactive text-based database query system. When the
user enters and executes a query, the query (the entire contents
of the text widget) is added to the history list. The user may
view previous queries and either execute them again or modify them
and execute the new query. If a previously executed query is
modified, the user may undo or redo all changes made to the query
<em>before the query is executed</em>.</p>
<p></p>
</dd>
<dt> <h3>Options</h3></dt><dd>
Options for this megawidget and its base
classes are described below.<p></p>
<a name=option.borderframe></a>
<dl><dt> <strong>borderframe
</strong></dt><dd>
Initialisation option. If true, the <strong>borderframe</strong> component will be created. The default is <strong>0</strong>.</p>
</dd></dl>
<a name=option.columnheader></a>
<dl><dt> <strong>columnheader
</strong></dt><dd>
Initialisation option. If true, the <strong>columnheader</strong> component will be created. The default is <strong>0</strong>.</p>
</dd></dl>
<a name=option.compressany></a>
<dl><dt> <strong>compressany
</strong></dt><dd>
See <code>addhistory()</code>. The default is <strong>1</strong>.</p>
</dd></dl>
<a name=option.compresstail></a>
<dl><dt> <strong>compresstail
</strong></dt><dd>
See <code>addhistory()</code>. The default is <strong>1</strong>.</p>
</dd></dl>
<a name=option.historycommand></a>
<dl><dt> <strong>historycommand
</strong></dt><dd>
This is a callback to indicate whether the currently displayed
entry in the history list has a previous or next entry. The
callback is given two arguments, <em>prevstate</em> and <em>nextstate</em>. If
the currently displayed entry is first in the history list, then
<em>prevstate</em> is <strong>'disabled'</strong>, otherwise it is <strong>'normal'</strong>. If the
currently displayed entry is last in the history list, then
<em>nextstate</em> is <strong>'disabled'</strong>, otherwise it is <strong>'normal'</strong>. These
values can be used, for example, to modify the state of <strong>Next</strong> and
<strong>Previous</strong> buttons that call the <code>next()</code> and <code>prev()</code> methods. The default is <strong>None</strong>.</p>
</dd></dl>
<a name=option.hscrollmode></a>
<dl><dt> <strong>hscrollmode
</strong></dt><dd>
The horizontal scroll mode. If <strong>'none'</strong>, the horizontal scrollbar
will never be displayed. If <strong>'static'</strong>, the scrollbar will always
be displayed. If <strong>'dynamic'</strong>, the scrollbar will be displayed
only if necessary. The default is <strong>'dynamic'</strong>.</p>
</dd></dl>
<a name=option.labelmargin></a>
<dl><dt> <strong>labelmargin
</strong></dt><dd>
Initialisation option. If the <strong>labelpos</strong> option is not <strong>None</strong>, this specifies the
distance between the <strong>label</strong> component and the rest of the
megawidget. The default is <strong>0</strong>.</p>
</dd></dl>
<a name=option.labelpos></a>
<dl><dt> <strong>labelpos
</strong></dt><dd>
Initialisation option. Specifies where to place the <strong>label</strong> component. If not
<strong>None</strong>, it should be a concatenation of one or two of the
letters <strong>'n'</strong>, <strong>'s'</strong>, <strong>'e'</strong> and <strong>'w'</strong>. The first letter
specifies on which side of the megawidget to place the label.
If a second letter is specified, it indicates where on that
side to place the label. For example, if <strong>labelpos</strong> is <strong>'w'</strong>,
the label is placed in the center of the left hand side; if
it is <strong>'wn'</strong>, the label is placed at the top of the left
hand side; if it is <strong>'ws'</strong>, the label is placed at the
bottom of the left hand side.</p>
<p> If <strong>None</strong>, a label component is not created. The default is <strong>None</strong>.</p>
</dd></dl>
<a name=option.rowcolumnheader></a>
<dl><dt> <strong>rowcolumnheader
</strong></dt><dd>
Initialisation option. If true, the <strong>rowcolumnheader</strong> component will be created. The default is <strong>0</strong>.</p>
</dd></dl>
<a name=option.rowheader></a>
<dl><dt> <strong>rowheader
</strong></dt><dd>
Initialisation option. If true, the <strong>rowheader</strong> component will be created. The default is <strong>0</strong>.</p>
</dd></dl>
<a name=option.scrollmargin></a>
<dl><dt> <strong>scrollmargin
</strong></dt><dd>
Initialisation option. The distance between the scrollbars and the text widget. The default is <strong>2</strong>.</p>
</dd></dl>
<a name=option.usehullsize></a>
<dl><dt> <strong>usehullsize
</strong></dt><dd>
Initialisation option. If true, the size of the megawidget is determined solely by the
width and height options of the <strong>hull</strong> component.</p>
<p> Otherwise, the size of the megawidget is determined by the width
and height of the <strong>text</strong> component, along with the size and/or
existence of the other components, such as the label, the
scrollbars and the scrollmargin option. All these affect the
overall size of the megawidget. The default is <strong>0</strong>.</p>
</dd></dl>
<a name=option.vscrollmode></a>
<dl><dt> <strong>vscrollmode
</strong></dt><dd>
The vertical scroll mode. If <strong>'none'</strong>, the vertical scrollbar
will never be displayed. If <strong>'static'</strong>, the scrollbar will always
be displayed. If <strong>'dynamic'</strong>, the scrollbar will be displayed
only if necessary. The default is <strong>'dynamic'</strong>.</p>
</dd></dl>
</dd>
<dt> <h3>Components</h3></dt><dd>
Components created by this megawidget and its base
classes are described below.<p></p>
<a name=component.borderframe></a>
<dl><dt> <strong>borderframe
</strong></dt><dd>
A frame widget which snuggly fits around the text widget, to give
the appearance of a text border. It is created with a border so
that the text widget, which is created without a border, looks
like it has a border. By default, this component is a Tkinter.Frame.</p>
</dd></dl>
<a name=component.columnheader></a>
<dl><dt> <strong>columnheader
</strong></dt><dd>
A text widget with a default height of 1 displayed above the main
text widget and which scrolls horizontally in sync with the
horizontal scrolling of the main text widget. By default, this component is a Tkinter.Text. Its component group is <strong>Header</strong>.</p>
</dd></dl>
<a name=component.horizscrollbar></a>
<dl><dt> <strong>horizscrollbar
</strong></dt><dd>
The horizontal scrollbar. By default, this component is a Tkinter.Scrollbar. Its component group is <strong>Scrollbar</strong>.</p>
</dd></dl>
<a name=component.hull></a>
<dl><dt> <strong>hull
</strong></dt><dd>
This acts as the body for the entire megawidget. Other components
are created as children of the hull to further specialise this
class. By default, this component is a Tkinter.Frame.</p>
</dd></dl>
<a name=component.label></a>
<dl><dt> <strong>label
</strong></dt><dd>
If the <strong>labelpos</strong> option is not <strong>None</strong>, this component is
created as a text label for the megawidget. See the
<strong>labelpos</strong> option for details. Note that to set, for example,
the <strong>text</strong> option of the label, you need to use the <strong>label_text</strong>
component option. By default, this component is a Tkinter.Label.</p>
</dd></dl>
<a name=component.rowcolumnheader></a>
<dl><dt> <strong>rowcolumnheader
</strong></dt><dd>
A text widget displayed to the top left of the main text widget,
above the row header and to the left of the column header if they
exist. The widget is not scrolled automatically. By default, this component is a Tkinter.Text. Its component group is <strong>Header</strong>.</p>
</dd></dl>
<a name=component.rowheader></a>
<dl><dt> <strong>rowheader
</strong></dt><dd>
A text widget displayed to the left of the main text widget and
which scrolls vertically in sync with the vertical scrolling of
the main text widget. By default, this component is a Tkinter.Text. Its component group is <strong>Header</strong>.</p>
</dd></dl>
<a name=component.text></a>
<dl><dt> <strong>text
</strong></dt><dd>
The text widget which is scrolled by the scrollbars. If the
<strong>borderframe</strong> option is true, this is created with a borderwidth
of <strong>0</strong> to overcome a known problem with text widgets: if a widget
inside a text widget extends across one of the edges of the text
widget, then the widget obscures the border of the text widget.
Therefore, if the text widget has no border, then this overlapping
does not occur. By default, this component is a Tkinter.Text.</p>
</dd></dl>
<a name=component.vertscrollbar></a>
<dl><dt> <strong>vertscrollbar
</strong></dt><dd>
The vertical scrollbar. By default, this component is a Tkinter.Scrollbar. Its component group is <strong>Scrollbar</strong>.</p>
</dd></dl>
</dd>
<a name=methods></a>
<dt> <h3>Methods</h3></dt><dd>
Only methods specific to this megawidget are described below.
For a description of its inherited methods, see the
manual for its base class
<strong><a href="ScrolledText.html#methods">Pmw.ScrolledText</a></strong>.
<p></p>
<a name=method.addhistory></a>
<dl><dt> <strong>addhistory</strong>()</dt><dd>
Append the currently displayed text to the history list.</p>
<p> If <strong>compressany</strong> is true, a new entry will be added to the history
list only if the currently displayed entry has changed.</p>
<p> If <strong>compresstail</strong> is true, a new entry will be added to the
history list only if the currently displayed entry has changed
<em>or</em> if it is not the last entry in the history list.</p>
</dd></dl>
<a name=method.gethistory></a>
<dl><dt> <strong>gethistory</strong>()</dt><dd>
Return the history list. Each entry in the list is a 3-tuple.
The first item in a history entry is the original text as added by
<code>addhistory()</code>. The second item is the edited text (if the user
has modified the entry but <code>addhistory()</code> has not yet been called
on the text). The third item specifies whether the entry should
currently display the original or modified text.</p>
</dd></dl>
<a name=method.next></a>
<dl><dt> <strong>next</strong>()</dt><dd>
Display the next screen in the history list.</p>
</dd></dl>
<a name=method.prev></a>
<dl><dt> <strong>prev</strong>()</dt><dd>
Display the previous screen in the history list.</p>
</dd></dl>
<a name=method.redo></a>
<dl><dt> <strong>redo</strong>()</dt><dd>
Reverse the effect of <code>undo()</code>.</p>
</dd></dl>
<a name=method.undo></a>
<dl><dt> <strong>undo</strong>()</dt><dd>
Undo all changes made since this entry was added to the history
list.</p>
</dd></dl>
</dd>
<dt> <h3>Example</h3></dt><dd>
The image at the top of this manual is a snapshot
of the window (or part of the window) produced
by the following code.<p></p>
<pre>
class Demo:
def __init__(self, parent):
# Create and pack the PanedWidget to hold the query and result
# windows.
# !! panedwidget should automatically size to requested size
panedWidget = Pmw.PanedWidget(parent,
orient = 'vertical',
hull_height = 400,
hull_width = 550)
panedWidget.add('query', min = 0.05, size = 0.2)
panedWidget.add('buttons', min = 0.1, max = 0.1)
panedWidget.add('results', min = 0.05)
panedWidget.pack(fill = 'both', expand = 1)
# Create and pack the HistoryText.
self.historyText = Pmw.HistoryText(panedWidget.pane('query'),
text_wrap = 'none',
text_width = 60,
text_height = 10,
historycommand = self.statechange,
)
self.historyText.pack(fill = 'both', expand = 1)
self.historyText.component('text').focus()
buttonList = (
[20, None],
['Clear', self.clear],
['Undo', self.historyText.undo],
['Redo', self.historyText.redo],
[20, None],
['Prev', self.historyText.prev],
['Next', self.historyText.next],
[30, None],
['Execute', Pmw.busycallback(self.executeQuery)],
)
self.buttonDict = {}
buttonFrame = panedWidget.pane('buttons')
for text, cmd in buttonList:
if type(text) == type(69):
frame = Tkinter.Frame(buttonFrame, width = text)
frame.pack(side = 'left')
else:
button = Tkinter.Button(buttonFrame, text = text, command = cmd)
button.pack(side = 'left')
self.buttonDict[text] = button
for text in ('Prev', 'Next'):
self.buttonDict[text].configure(state = 'disabled')
self.results = Pmw.ScrolledText(panedWidget.pane('results'), text_wrap = 'none')
self.results.pack(fill = 'both', expand = 1)
def statechange(self, prevstate, nextstate):
self.buttonDict['Prev'].configure(state = prevstate)
self.buttonDict['Next'].configure(state = nextstate)
def clear(self):
self.historyText.delete('1.0', 'end')
def addnewlines(self, text):
if len(text) == 1:
text = text + '\n'
if text[-1] != '\n':
text = text + '\n'
if text[-2] != '\n':
text = text + '\n'
return text
def executeQuery(self):
sql = self.historyText.get()
self.results.insert('end', 'Query:\n' + self.addnewlines(sql))
self.results.see('end')
self.results.update_idletasks()
self.historyText.addhistory()
results = 'Results:\nfoo'
if len(results) > 0:
self.results.insert('end', self.addnewlines(results))
self.results.see('end')
</pre>
</dd>
</dl>
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Pmw 1.3 -
7 Aug 2007
- <a href="index.html">Home</a>
<br>Manual page last reviewed: 20 May 2002
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