Sunday, June 28, 2009

wxRuby: Changing Text Fonts and Colours

A reader recently asked me how to change the text font size and color for wxRuby controls such as the StaticText control. Let's take a look at how you can do this.

Imagine, if you will, that we have a StaticText control named my_control...

Changing Fonts

We'll begin by creating a new Font object by calling the Font.new() method:


my_font = Wx::Font.new()

Next, we'll set various attributes of our new Font object:

my_font.set_point_size(20)
my_font.set_family(Wx::FONTFAMILY_MODERN)
my_font.set_style(Wx::FONTSTYLE_ITALIC)
my_font.set_weight(Wx::FONTWEIGHT_BOLD)

Once we have our Font object defined to our satisfaction, we can then pass it to our control's set_font() method:

my_control.set_font(my_font)

Changing Colors

Text color is not an attribute of the Font object, but is rather the foreground color of the control. So, to change the color of the text, we call the control's set_foreground_colour() method and pass it a Colour object. We'll make it easy and use one of wxRuby's built-in Colour constants:

my_control.set_foreground_colour(Wx::RED)

Make a note of the spelling: colour, not color.

Further Reading

A simple working example can be found here.

Documentation of the Font object can be found here.

Documentation of the set_foreground_colour() method can be found here.

Documentation of the Colour object can be found here.

And there you have it. Let me know if you'd like to see more on this or other subjects.

Thanks for stopping by!

Tuesday, June 23, 2009

Ruby & Word: Inserting Tables

Microsoft Word is great for text documents. Microsoft Excel is great for tables of data. But, sometimes, you need to get your chocolate in your peanut butter. In other words, you may occasionally need to include a table in a Word document. Let's walk through how to do that.

Setting the Stage

To borrow an example from my upcoming book, let's say that you want to insert a table that contains a list of all movies starring Spencer Tracy and Katharine Hepburn, including the year each movie was released, the title, and the director. Your 2-dimensional films array might look like this:


films = []
films << ["1942", "Woman of the Year", "George Stevens"]
films << ["1942", "Keeper of the Flame", "George Cukor"]
films << ["1945", "Without Love", "Harold S. Bucquet"]
films << ["1947", "The Sea of Grass", "Elia Kazan"]
films << ["1948", "State of the Union", "Frank Capra"]
films << ["1949", "Adam's Rib", "George Cukor"]
films << ["1952", "Pat and Mike", "George Cukor"]
films << ["1957", "Desk Set", "Walter Lang"]
films << ["1967", "Guess Who's Coming to Dinner", "Stanley Kramer"]

Let's connect to a running instance of Word and use the currently selected document:

require 'win32ole'
word = WIN32OLE.connect('Word.Application')
doc = word.ActiveDocument

Moving to the End of the Document

First, let's move to the end of the document, where we'll add our new table. We do this by calling the Selection.EndKey() method, which moves the selection to the end of a word, line, or document. We'll pass this method a value of 6, which specifies that we want to move to the end of the document:

word.Selection.EndKey(6)

Adding a New Table

The Tables collection in Word's object model represents all the Table objects in a selection, range, or document. To add a new Table to a document, call the Document object's Tables.Add() method and pass it three parameters:

* The range object representing where the table is to be inserted
* The number of rows for the new table
* The number of columns for the new table

Now let's add a new table with one row and three columns (we'll add more rows later):

table = doc.Tables.Add(word.Selection.Range, 1, 3)

The Tables.Add() method returns a reference to the newly created table, which we have assigned to the cleverly named variable table.

Inserting Text into Table Cells

You can reference a single cell in a table by calling the Cell() method and passing it the row and column numbers (NOTE: the first row or column is represented by 1, not 0). Once you have your cell, you can set the text via its Range.Text property; so we add the header text as follows:

table.Cell(1, 1).Range.Text = 'Year'
table.Cell(1, 2).Range.Text = 'Film Title'
table.Cell(1, 3).Range.Text = 'Director'

Adding Rows

To add a row to your table, simply call the Table object's Rows.Add() method. Now that we've added the header text, let's iterate over our films array and add a new row to the table for each film and insert the text:

films.each_with_index do |film, r|
table.Rows.Add()
film.each_with_index do |field, c|
table.Cell(r + 2, c + 1).Range.Text = field
end
end

There you have it. Thanks for stopping by!

Friday, June 12, 2009

Ruby & Word: Counting Words and Pages

Someone recently asked how to get a count of the number of words and pages in a Microsoft Word document. This is done by calling the ComputeStatistics() method on a Range or Document object.

As an example (play along at home), let's imagine that you have a Word document open. Your first step is to use the win32ole library's connect() method to connect to the existing instance of Word:


require 'win32ole'
word = WIN32OLE.connect('Word.Application')

You pass the ComputeStatistics() method an integer representing the type of statistic that you want to calculate. In other words, "What do you want to count?" So let's take a moment to define constants for those values:

WdStatisticCharacters = 3
WdStatisticCharactersWithSpaces = 5
WdStatisticWords = 0
WdStatisticLines = 1
WdStatisticParagraphs = 4
WdStatisticPages = 2

You can call the ComputeStatistics() method on a Document object...

doc = word.ActiveDocument
word_count = doc.ComputeStatistics(WdStatisticWords)
page_count = doc.ComputeStatistics(WdStatisticPages)

...or on a Range object...

paragraph = doc.Paragraphs(27)
word_count = paragraph.Range.ComputeStatistics(WdStatisticWords)
char_count = paragraph.Range.ComputeStatistics(WdStatisticCharacters)

When called on a Document object, the method accepts an optional second parameter, IncludeFootnotesAndEndnotes, a boolean which (obviously) specifies if the calculation should include footnotes and endnotes:

word_count = doc.ComputeStatistics(WdStatisticWords, true)

The IncludeFootnotesAndEndnotes parameter defaults to false.

Official details on the ComputeStatistics() method are available from MSDN here.

That's all for now. Thanks for stopping by!

Thursday, June 4, 2009

Ruby & Word: Creating and Applying Styles

Microsoft Word uses the Styles model to apply a set of pre-defined formatting to text. Styles can also serve a second purpose, to tag sections of the document as normal, title, headings and such. You can then, for example, create a Table of Contents in Word based on the text that is formatted with the Heading styles.

Naturally, you can do all this with code (otherwise, I wouldn't be wasting your time here). Over the next few minutes, we'll walk through the process of creating a new Style, setting its properties, and then applying that style to text.

The Style object represents a single built-in or user-defined Word style. The Styles collection contains all the Style objects within a document. To reference the Styles collection, simply call the Styles method on the document:


doc = word.ActiveDocument
styles = doc.Styles

To create a new Style, we call the Add() method on the Styles object and pass it a hash defining the name and the type of the new Style. The following code creates a new Paragraph style named 'Code':

code_style = doc.Styles.Add({'Name' => 'Code', 'Type' => 1})

The Type property defines what StyleType your new Style is based on. Possible values are:

WdStyleTypeParagraph = 1
wdStyleTypeCharacter = 2
WdStyleTypeTable = 3
WdStyleTypeList = 4

The default is WdStyleTypeParagraph.

The Add() method returns a reference to the newly-created Style object. Now that you have your new Style object, you can customize it through various properties that you can set. As a starting point, you may want to base your new style on another style by setting the BaseStyle property:

code_style.BaseStyle = 'Normal'

Font properties can be defined...

code_style.Font.Name = 'Consolas'
code_style.Font.Size = 12
code_style.Font.Bold = false

...as well as paragraph spacing and background colors:

code_style.NoSpaceBetweenParagraphsOfSameStyle = true
code_style.Shading.BackgroundPatternColor = 15132390

Note that not all properties will apply to all style types.

Now that you've created your own Style, you might want to automatically apply it to some existing text. The following code iterates over each paragraph in the document (doc variable). For each paragraph that uses the 'Preformatted Text' style, the new 'Code' style is applied instead:

doc.Paragraphs.each do |paragraph|
if paragraph.Style.NameLocal == 'Preformatted Text'
paragraph.Style = 'Code'
end
end

There you have it. If you'd like to learn more here about Styles, or anything else related to automating Word with Ruby, please let me know.

Thanks for stopping by!

Sunday, May 24, 2009

The OCRA Compiler: Tips, Tricks, and Gotchas

I've previously mentioned Lars Christensen's One-Click Ruby Application Builder, a "compiler" for Ruby scripts that shows a lot of potential (and current value). There's not much documentation yet, but folks are installing it, using it, and providing feedback. It works right out of the box for many purposes, but here are a few things to keep in mind as you use it...

"Failed to create directory" Error

One user reported receiving the error "Failed to create directory" when running the compiled executable. As a possible workaround, try running ocra.rb from the directory where your script is located. For example, instead of running...


ocra.rb "C:\code\rubyscripts\application.rbw"

...navigate to the "C:\code\rubyscripts" directory, then run:

ocra.rb application.rbw

Note that while this resolved the problem on my machine, it didn't help the person who originally reported the problem.

Require RubyGems

When you compile your script (which uses one or more gems) with OCRA and then run the executable, you may receive a 'no such file to load' error. Try adding the line...

require 'rubygems'

...to the top of your script, above the other require statements. I've found that a script that runs pre-compiled without this statement may not execute once compiled.

Compile Without Running

I mentioned earlier that it would be nice to have an option to avoid fully running the script, similar to RubyScript2Exe's exit if RUBYSCRIPT2EXE.is_compiling? idiom. A tip of the hat goes to reader "BackOrder", who offered the following solution:

exit if Object.const_defined?(:Ocra)

Put all your require statements at the top of your code, followed by this line.

OCRA and Mechanize: "libxml2.dll not found"

There may be a problem compiling a script that requires the mechanize gem. Running the compiled executable resulted in a "libxml2.dll was not found" error on my machine.

Note that the above observations relate to version 1.0.2 (current as of this writing) of the ocra gem.

More information is available in the OCRA forums and bug tracker.

Thanks again to Lars for creating OCRA, and to the users who have installed it, used it, and provided their feedback.

Thanks for stopping by!

Sunday, May 17, 2009

Handling WIN32OLE Events in Excel

Someone recently asked how to have Ruby react to events in Excel. Specifically, they were trying retrieve the contents of a row in a worksheet when it's selected.

The win32ole module provides a WIN32OLE_EVENT class that will allow you to execute a block of code when a specific event occurs.

To set the scene, let's use the WIN32OLE.connect() method to connect to an existing instance of Microsoft Excel and grab a reference to the currently active workbook:


require 'win32ole'
xl = WIN32OLE.connect('Excel.Application')
wb = xl.ActiveWorkbook

Next, we'll call the WIN32OLE_EVENT.new() method to create a new OLE event object. You pass this method an OLE object---our Workbook object---and the name of the event sink. In this instance, we want to use the WorkbookEvents sink:

ev = WIN32OLE_EVENT.new(wb, 'WorkbookEvents')

Once you have your event sink defined, you call its on_event() method to hook into a particular event and run a block of code when that event fires. In our scenario, we want to take action when the SheetSelectionChange event fires.

ev.on_event('SheetSelectionChange') do
range = xl.Selection
puts(range.Value)
STDOUT.flush()
end

The above block of code will execute when the user selects a range of cells, and will print out the array of values from the selected cells.

Finally, you need to start the event message loop to begin the event monitoring:

loop do
WIN32OLE_EVENT.message_loop
end

In the real world, we need a means to exit the message loop. Let's catch the BeforeClose event, which fires (of course) just prior to the workbook being closed:

ev.on_event('BeforeClose') do
exit_event_loop
end

Now, when the BeforeClose event fires, we'll have it call a new exit_event_loop() method, which sets a $LOOP value to false:

$LOOP = true

def exit_event_loop
$LOOP = false
end

Finally, we'll modify our earlier message loop block, accordingly, and also toss in a brief pause:

while $LOOP
WIN32OLE_EVENT.message_loop
sleep(0.1)
end

Our complete code looks something like this:

require 'win32ole'

xl = WIN32OLE.connect('Excel.Application')
wb = xl.ActiveWorkbook

ev = WIN32OLE_EVENT.new(wb, 'WorkbookEvents')

ev.on_event('SheetSelectionChange') do
range = xl.Selection
puts(range.Value)
STDOUT.flush()
end

ev.on_event('BeforeClose') do
puts('Closed');STDOUT.flush
exit_event_loop
end

$LOOP = true

def exit_event_loop
$LOOP = false
end

while $LOOP
WIN32OLE_EVENT.message_loop
sleep(0.1)
end

And there you have it. Tweak to suit your individual needs.

Thanks for stopping by!

Thursday, May 14, 2009

OCRA: One-Click Ruby Application Builder

I recently mentioned the fact that RubyScript2Exe 0.5.3 doesn't play well with recent versions of RubyGems. At the end of that post I mentioned that there are alternatives emerging for creating executables from your Ruby code, including Lars Christensen's OCRA, the One-Click Ruby Application Builder.

I've had a chance to take OCRA for a short test drive and it looks promising. Like Erik Veenstra's RubyScript2Exe, OCRA lets you "compile" your ruby code into an EXE file that you can distribute to others, without requiring that the users have Ruby installed on their PCs. To quote the OCRA page:

The executable is a self-extracting, self-running executable that contains the Ruby interpreter, your source code and any additionally needed ruby libraries or DLL.

OCRA can be installed via RubyGems: open a console window and type:

gem install ocra

It's also available from the RubyForge page. Version 1.0.2 is the latest as of this writing.

The syntax to compile a script is...

ocra.rb [option] your/script.rb

...where option is one or more of the following:

--dll dllname Include additional DLLs from the Ruby bindir.
--no-lzma Disable LZMA compression of the executable.
--quiet Suppress output.
--help Display this information.
--windows Force Windows application (rubyw.exe)
--console Force console application (ruby.exe)
--no-autoload Don't load/include script.rb's autoloads

Thus far, I have exercised only the --windows and --console options.

To create a non-console application, either use the --windows option or give your script the .rbw filename extension. Compiling a basic non-console script is as simple as opening a console window, navigating to the folder containing your script, and typing:

ocra.rb myscript.rbw

OCRA will then run your script to check for dependencies, gather the necessary files, and create your executable. An option to avoid fully running the script would be nice, similar to RubyScript2Exe's exit if RUBYSCRIPT2EXE.is_compiling? idiom.

OCRA uses LZMA compression, so the resulting executable is relatively small. A simple wxRuby app, for example, resulted in a 2.5 Mb executable. The same app compiled with RubyScript2Exe weighed in at over 9 Mb. Apps that do not require a GUI toolkit will be even smaller, perhaps 500k.

I haven't spent a lot of time with OCRA yet, but I think it shows great potential and I want to thank Lars Christensen for his efforts. If you have a need to distribute Ruby programs to non-technical users, you should check it out and pass your feedback along to Lars.

Thanks for stopping by!