From: Matthew Borgeson <hibridmatthias@...>
Date: 2009-08-05T06:50:22+09:00
Subject: QtRuby Questions: Why does

Guten Tag, everyone-

I have finally found the time to sit down and attempt GUI programming
with QtRuby. I am attempting to use QtRuby from within KDevelop to make
a simple widget in Qt Designer, run the .ui file through rbuic, and then
simply modify the connections.

The widget in question has 3 lineEdit fields, all three of which begin
blank. Ultimately, I want eventually to have the lineEdit3 field
(labeled "sum") to "automagically" populate with the sum of the first
two lineEdit fields once the user had entered non-zero numbers.

My current goal is to simply have the lineEdit3 field "automagically"
display the word "fudge" whenever a number is simply entered into
lineEdit1, I have looked at the Rapid GUI Development Fridays book, The
Ruby Way, and various online tutorials to help me with this to no avail.

Here is the code so far:

# Form implementation generated from reading ui file 'sum.ui'
#
# Created: Mon Aug 3 16:38:58 2009
#      by: The QtRuby User Interface Compiler (rbuic)
#
# WARNING! All changes made in this file will be lost!


require 'Qt'

class Form1 < Qt::Widget
slots
    attr_reader :textLabel1
    attr_reader :textLabel2
    attr_reader :textLabel3
    attr_reader :pushButton1
    attr_reader :lineEdit1
    attr_reader :lineEdit2
    attr_reader :lineEdit3

#start my slots
'update(const QString &)'
#end my slots

    def initialize(parent = nil, name = nil, fl = 0)
        super

        if name.nil?
                setName("Form1")
        end

#start my variables

#end my variables

        @textLabel1 = Qt::Label.new(self, "textLabel1")
        @textLabel1.setGeometry( Qt::Rect.new(160, 50, 111, 31) )

        @textLabel2 = Qt::Label.new(self, "textLabel2")
        @textLabel2.setGeometry( Qt::Rect.new(160, 90, 121, 31) )

        @textLabel3 = Qt::Label.new(self, "textLabel3")
        @textLabel3.setGeometry( Qt::Rect.new(150, 140, 121, 31) )

        @pushButton1 = Qt::PushButton.new(self, "pushButton1")
        @pushButton1.setGeometry( Qt::Rect.new(270, 50, 71, 31) )

        @lineEdit1 = Qt::LineEdit.new(self, "lineEdit1")
        @lineEdit1.setGeometry( Qt::Rect.new(30, 50, 90, 31) )

        @lineEdit2 = Qt::LineEdit.new(self, "lineEdit2")
        @lineEdit2.setGeometry( Qt::Rect.new(30, 90, 90, 31) )

        @lineEdit3 = Qt::LineEdit.new(self, "lineEdit3")
        @lineEdit3.setGeometry( Qt::Rect.new(30, 140, 90, 31) )

#start my connections
Qt::Object.connect(@lineEdit1, SIGNAL("textChanged(const QString &)"),
                   @lineEdit3, SLOT('update(const QString &)') )

Qt::Object.connect(@pushButton1, SIGNAL("clicked()"), @lineEdit1,
SLOT("clear()") )
Qt::Object.connect(@pushButton1, SIGNAL("clicked()"), @lineEdit2,
SLOT("clear()") )
Qt::Object.connect(@pushButton1, SIGNAL("clicked()"), @lineEdit3,
SLOT("clear()") )

#end my connections

        languageChange()
        resize( Qt::Size.new(581, 480).expandedTo(minimumSizeHint()) )
        clearWState( WState_Polished )
    end

#start my slot methods
  def update
    @lineEdit3.setText( trUtf8("fudge"))
  end
#end my slot methods

    #
    #  Sets the strings of the subwidgets using the current
    #  language.
    #
    def languageChange()
        setCaption(trUtf8("Form1"))
        @textLabel1.setText( trUtf8("addend 1") )
        @textLabel2.setText( trUtf8("addend 2") )
        @textLabel3.setText( trUtf8("sum") )
        @pushButton1.setText( trUtf8("Reset") )
    end
    protected :languageChange


end


Here is the error message I get when I try to run it:

ruby -KA -C"/home/hujraad/Desktop/sum" -I"/home/hujraad/Desktop/sum/."
"sum.rb"
QObject::connect: No such slot Qt::LineEdit::update(const QString&)
QObject::connect:  (sender name:   'lineEdit1')
QObject::connect:  (receiver name: 'lineEdit3')
*** Exited normally ***


I believe I have the connections in correctly, as I have already
practiced that with other connections. Have I improperly syntaxed the
update() method?

any help is appreciated; thanks in advance


Matthew Borgeson
-- 
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