Development/Tutorials/Qt4 Ruby Tutorial/Chapter 07 - Revision history

AnneW at 14:19, 18 July 2012

2012-07-18T14:19:39Z

Aspotashev: add link to chapter 6

2011-07-02T17:48:45Z

add link to chapter 6

AnneW: Marked this version for translation

2011-07-02T14:54:14Z

Marked this version for translation

Aspotashev: remove links to files from translation

2011-07-01T23:33:09Z

remove links to files from translation

Aspotashev: add translate tags

2011-07-01T23:26:06Z

add translate tags

Neverendingo: Text replace - "" to ""

2011-06-29T20:55:29Z

Text replace - "</code>" to "</syntaxhighlight>"

Neverendingo: Text replace - "`" to ""`


2011-06-29T20:43:07Z
Text replace - "<code ruby>" to "<syntaxhighlight lang="ruby">"

				
				
				
				
			
			← Older revision
			Revision as of 20:43, 29 June 2011
			
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  This file is mainly lifted from Chapter 6; only the non-trivial changes are noted here.   This file is mainly lifted from Chapter 6; only the non-trivial changes are noted here.
    
− <code ruby> + <syntaxhighlight lang="ruby">
  signals 'valueChanged(int)'   signals 'valueChanged(int)'
  slots 'setValue(int)'   slots 'setValue(int)'
  </code>   </code>
− <code ruby> + <syntaxhighlight lang="ruby">
  def value()   def value()
     @slider.value()      @slider.value()
Line 51:
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  The implementation of '''<tt>setValue()</tt>''' is equally straightforward. Note that because the slider and LCD number are connected, setting the slider's value automatically updates the LCD number as well. In addition, the slider will automatically adjust the value if it is outside its legal range.   The implementation of '''<tt>setValue()</tt>''' is equally straightforward. Note that because the slider and LCD number are connected, setting the slider's value automatically updates the LCD number as well. In addition, the slider will automatically adjust the value if it is outside its legal range.
    
− <code ruby> + <syntaxhighlight lang="ruby">
  connect(@slider, SIGNAL('valueChanged(int)'),   connect(@slider, SIGNAL('valueChanged(int)'),
           lcd, SLOT('display(int)'))            lcd, SLOT('display(int)'))
Line 67:
Line 67:
    
  '''[http://www.darshancomputing.com/qt4-qtruby-tutorial/tutorial/t7/t7.rb t7.rb]'''   '''[http://www.darshancomputing.com/qt4-qtruby-tutorial/tutorial/t7/t7.rb t7.rb]'''
− <code ruby> + <syntaxhighlight lang="ruby">
  previousRange = nil   previousRange = nil



Alisha at 03:01, 13 January 2010
2010-01-13T03:01:30Z


				
				
				
				
			
			← Older revision
			Revision as of 03:01, 13 January 2010
			
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  === Running the Application ===   === Running the Application ===
−  
  On startup, the program's appearance is identical to the previous one. Try operating the slider to the bottom-right.   On startup, the program's appearance is identical to the previous one. Try operating the slider to the bottom-right.
    
  === Exercises ===   === Exercises ===
−  
  Use the bottom-right slider to set all LCDs to 50. Then set all but the last LCD to 40 by clicking once to the left of the bottom-middle slider handle. Now, use the bottom-left slider to set the first seven LCDs back to 50.   Use the bottom-right slider to set all LCDs to 50. Then set all but the last LCD to 40 by clicking once to the left of the bottom-middle slider handle. Now, use the bottom-left slider to set the first seven LCDs back to 50.
    
  Click to the left of the handle on the bottom-right slider. What happens? Why is this the correct behavior?   Click to the left of the handle on the bottom-right slider. What happens? Why is this the correct behavior?
  + 
  + [[Category:Ruby]]





Alisha at 16:22, 3 January 2010
2010-01-03T16:22:05Z


				
				
				
				
			
			← Older revision
			Revision as of 16:22, 3 January 2010
			
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  Let's look at what happens when the user operates the slider. The slider sees that its value has changed and emits the [http://doc.qt.nokia.com/latest/qabstractslider.html#valueChanged QAbstractSlider::valueChanged()] signal. That signal is connected both to the [http://doc.qt.nokia.com/latest/qlcdnumber.html#intValue-prop QLCDNumber::display()] slot of the [http://doc.qt.nokia.com/latest/qlcdnumber.html Qt::LCDNumber] and to the '''<tt>valueChanged()</tt>''' signal of the '''<tt>LCDRange</tt>'''.   Let's look at what happens when the user operates the slider. The slider sees that its value has changed and emits the [http://doc.qt.nokia.com/latest/qabstractslider.html#valueChanged QAbstractSlider::valueChanged()] signal. That signal is connected both to the [http://doc.qt.nokia.com/latest/qlcdnumber.html#intValue-prop QLCDNumber::display()] slot of the [http://doc.qt.nokia.com/latest/qlcdnumber.html Qt::LCDNumber] and to the '''<tt>valueChanged()</tt>''' signal of the '''<tt>LCDRange</tt>'''.
    
− Thus, when the signal is emitted, LCDRange emits its own '''<tt>valueChanged()</tt>''' signal. In addition, [http://doc.qt.nokia.com/latest/qlcdnumber.html#intValue-prop QLCDNumber::display()] is called and shows the new number. + Thus, when the signal is emitted, '''<tt>LCDRange</tt>''' emits its own '''<tt>valueChanged()</tt>''' signal. In addition, [http://doc.qt.nokia.com/latest/qlcdnumber.html#intValue-prop QLCDNumber::display()] is called and shows the new number.
    
− Note that you're not guaranteed any particular order of execution; LCDRange::valueChanged() may be emitted before or after [http://doc.qt.nokia.com/latest/qlcdnumber.html#intValue-prop QLCDNumber::display()] is called. + Note that you're not guaranteed any particular order of execution; '''<tt>LCDRange::valueChanged()</tt>''' may be emitted before or after [http://doc.qt.nokia.com/latest/qlcdnumber.html#intValue-prop QLCDNumber::display()] is called.
    
  '''[http://www.darshancomputing.com/qt4-qtruby-tutorial/tutorial/t7/t7.rb t7.rb]'''   '''[http://www.darshancomputing.com/qt4-qtruby-tutorial/tutorial/t7/t7.rb t7.rb]'''
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  </code>   </code>
    
− When we create the nine '''<tt>LCDRange</tt>''' objects, we connect them using the [http://doc.qt.nokia.com/latest/signalsandslots.html signals and slots] mechanism. Each has its '''<tt>valueChanged()</tt>''' signal connected to the previous one's '''<tt>setValue()</tt>''' slot. Because LCDRange emits the '''<tt>valueChanged()</tt>''' signal when its value changes, we are here creating a chain of signals and slots. + When we create the nine '''<tt>LCDRange</tt>''' objects, we connect them using the [http://doc.qt.nokia.com/latest/signalsandslots.html signals and slots] mechanism. Each has its '''<tt>valueChanged()</tt>''' signal connected to the previous one's '''<tt>setValue()</tt>''' slot. Because '''<tt>LCDRange</tt>''' emits the '''<tt>valueChanged()</tt>''' signal when its value changes, we are here creating a chain of signals and slots.
    
  === Running the Application ===   === Running the Application ===





Alisha at 16:12, 30 December 2009
2009-12-30T16:12:50Z


				
				
				
				
			
			← Older revision
			Revision as of 16:12, 30 December 2009
			
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  </code>   </code>
    
− The first [http://doc.qt.nokia.com/latest/qobject.html#connect QObject::connect()] call is the same that you have seen in the previous chapter. The second is new; it connects slider's QAbstractSlider::valueChanged() signal to this object's '''<tt>valueChanged()</tt>''' signal. Yes, that's right. Signals can be connected to other signals. When the first is emitted, the second signal is also emitted. + The first [http://doc.qt.nokia.com/latest/qobject.html#connect QObject::connect()] call is the same that you have seen in the previous chapter. The second is new; it connects slider's [http://doc.qt.nokia.com/latest/qabstractslider.html#valueChanged QAbstractSlider::valueChanged()] signal to this object's '''<tt>valueChanged()</tt>''' signal. Yes, that's right. Signals can be connected to other signals. When the first is emitted, the second signal is also emitted.
    
− Let's look at what happens when the user operates the slider. The slider sees that its value has changed and emits the QAbstractSlider::valueChanged() signal. That signal is connected both to the QLCDNumber::display() slot of the Qt::LCDNumber and to the '''<tt>valueChanged()</tt>''' signal of the '''<tt>LCDRange</tt>'''. + Let's look at what happens when the user operates the slider. The slider sees that its value has changed and emits the [http://doc.qt.nokia.com/latest/qabstractslider.html#valueChanged QAbstractSlider::valueChanged()] signal. That signal is connected both to the [http://doc.qt.nokia.com/latest/qlcdnumber.html#intValue-prop QLCDNumber::display()] slot of the [http://doc.qt.nokia.com/latest/qlcdnumber.html Qt::LCDNumber] and to the '''<tt>valueChanged()</tt>''' signal of the '''<tt>LCDRange</tt>'''.
    
− Thus, when the signal is emitted, LCDRange emits its own '''<tt>valueChanged()</tt>''' signal. In addition, Qt::LCDNumber::display() is called and shows the new number. + Thus, when the signal is emitted, LCDRange emits its own '''<tt>valueChanged()</tt>''' signal. In addition, [http://doc.qt.nokia.com/latest/qlcdnumber.html#intValue-prop QLCDNumber::display()] is called and shows the new number.
    
− Note that you're not guaranteed any particular order of execution; LCDRange::valueChanged() may be emitted before or after Qt::LCDNumber::display() is called. + Note that you're not guaranteed any particular order of execution; LCDRange::valueChanged() may be emitted before or after [http://doc.qt.nokia.com/latest/qlcdnumber.html#intValue-prop QLCDNumber::display()] is called.
    
  '''[http://www.darshancomputing.com/qt4-qtruby-tutorial/tutorial/t7/t7.rb t7.rb]'''   '''[http://www.darshancomputing.com/qt4-qtruby-tutorial/tutorial/t7/t7.rb t7.rb]'''
Line 83:
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  </code>   </code>
    
− When we create the nine '''<tt>LCDRange</tt>''' objects, we connect them using the signals and slots mechanism. Each has its '''<tt>valueChanged()</tt>''' signal connected to the previous one's '''<tt>setValue()</tt>''' slot. Because LCDRange emits the '''<tt>valueChanged()</tt>''' signal when its value changes, we are here creating a chain of signals and slots. + When we create the nine '''<tt>LCDRange</tt>''' objects, we connect them using the [http://doc.qt.nokia.com/latest/signalsandslots.html signals and slots] mechanism. Each has its '''<tt>valueChanged()</tt>''' signal connected to the previous one's '''<tt>setValue()</tt>''' slot. Because LCDRange emits the '''<tt>valueChanged()</tt>''' signal when its value changes, we are here creating a chain of signals and slots.
    
  === Running the Application ===   === Running the Application ===

@@ Line 1: / Line 1: @@
 <languages />
-{{Template:I18n/Language Navigation Bar|Development/Tutorials/Qt4 Ruby Tutorial/Chapter 07}}
 {{<translate><!--T:1-->

@@ Line 43: / Line 43: @@
 <translate>
 <!--T:12-->
-This file is mainly lifted from Chapter 6; only the non-trivial changes are noted here.
+This file is mainly lifted from [[Special:myLanguage/Development/Tutorials/Qt4_Ruby_Tutorial/Chapter_06|Chapter 6]]; only the non-trivial changes are noted here.
 </translate>

@@ Line 3: / Line 3: @@
 {{Template:I18n/Language Navigation Bar|Development/Tutorials/Qt4 Ruby Tutorial/Chapter 07}}
-{{<translate>TutorialBrowser</translate>|
+{{<translate><!--T:1-->
-series=[[Special:myLanguage/Development/Tutorials/Qt4_Ruby_Tutorial|<translate>Qt4 Ruby Tutorial</translate>]]|
+TutorialBrowser</translate>|
-name=<translate>One Thing Leads to Another</translate>|
+series=[[Special:myLanguage/Development/Tutorials/Qt4_Ruby_Tutorial|<translate><!--T:2-->
-pre=[[Special:myLanguage/Development/Tutorials/Qt4_Ruby_Tutorial/Chapter_06|<translate>Tutorial 6 - Building Blocks Galore!</translate>]]|
+Qt4 Ruby Tutorial</translate>]]|
-next=[[Special:myLanguage/Development/Tutorials/Qt4_Ruby_Tutorial/Chapter_08|<translate>Tutorial 8 - Preparing for Battle</translate>]]
+name=<translate><!--T:3-->
 }}
 <translate>
-== One Thing Leads to Another ==
+== One Thing Leads to Another == <!--T:6-->
 </translate>
 <translate>
 [[Image:Qt4_Ruby_Tutorial_Screenshot_7.png|center]]
 </translate>
 <translate>
 Files:
 </translate>
@@ Line 23: / Line 30: @@
 <translate>
-=== Overview ===
+=== Overview === <!--T:9-->
 This example shows how to create custom widgets with signals and slots, and how to connect them together in more complex ways. For the first time, the source is split among several files.
 </translate>
 <translate>
-=== Line by Line Walkthrough ===
+=== Line by Line Walkthrough === <!--T:11-->
 </translate>
 '''[http://www.darshancomputing.com/qt4-qtruby-tutorial/tutorial/t7/lcdrange.rb lcdrange.rb]'''
 <translate>
 This file is mainly lifted from Chapter 6; only the non-trivial changes are noted here.
 </translate>
@@ Line 52: / Line 61: @@
 <translate>
 These make up an interface between this widget and other components in a program. Until now, '''<tt>LCDRange</tt>''' didn't really have an API at all.
 '''<tt>value()</tt>''' is a public function for accessing the value of the '''<tt>LCDRange</tt>''', '''<tt>setValue()</tt>''' is our first custom slot, and '''<tt>valueChanged()</tt>''' is our first custom signal.
 Slots must be implemented in the normal way (a slot is also a Ruby member function). Signals are automatically implemented. Signals follow the access rules of protected Ruby functions (i.e., they can be emitted only by the class they are defined in or by classes inheriting from it).
 The '''<tt>valueChanged()</tt>''' signal is used when the '''<tt>LCDRange's</tt>''' value has changed.
 The implementation of '''<tt>value()</tt>''' is straightforward. It simply returns the slider's value.
 The implementation of '''<tt>setValue()</tt>''' is equally straightforward. Note that because the slider and LCD number are connected, setting the slider's value automatically updates the LCD number as well. In addition, the slider will automatically adjust the value if it is outside its legal range.
 </translate>
@@ Line 73: / Line 88: @@
 <translate>
 The first [http://doc.qt.nokia.com/latest/qobject.html#connect QObject::connect()] call is the same that you have seen in the previous chapter. The second is new; it connects slider's [http://doc.qt.nokia.com/latest/qabstractslider.html#valueChanged QAbstractSlider::valueChanged()] signal to this object's '''<tt>valueChanged()</tt>''' signal. Yes, that's right. Signals can be connected to other signals. When the first is emitted, the second signal is also emitted.
 Let's look at what happens when the user operates the slider. The slider sees that its value has changed and emits the [http://doc.qt.nokia.com/latest/qabstractslider.html#valueChanged QAbstractSlider::valueChanged()] signal. That signal is connected both to the [http://doc.qt.nokia.com/latest/qlcdnumber.html#intValue-prop QLCDNumber::display()] slot of the [http://doc.qt.nokia.com/latest/qlcdnumber.html Qt::LCDNumber] and to the '''<tt>valueChanged()</tt>''' signal of the '''<tt>LCDRange</tt>'''.
 Thus, when the signal is emitted, '''<tt>LCDRange</tt>''' emits its own '''<tt>valueChanged()</tt>''' signal. In addition, [http://doc.qt.nokia.com/latest/qlcdnumber.html#intValue-prop QLCDNumber::display()] is called and shows the new number.
 Note that you're not guaranteed any particular order of execution; '''<tt>LCDRange::valueChanged()</tt>''' may be emitted before or after [http://doc.qt.nokia.com/latest/qlcdnumber.html#intValue-prop QLCDNumber::display()] is called.
 </translate>
@@ Line 100: / Line 119: @@
 <translate>
 When we create the nine '''<tt>LCDRange</tt>''' objects, we connect them using the [http://doc.qt.nokia.com/latest/signalsandslots.html signals and slots] mechanism. Each has its '''<tt>valueChanged()</tt>''' signal connected to the previous one's '''<tt>setValue()</tt>''' slot. Because '''<tt>LCDRange</tt>''' emits the '''<tt>valueChanged()</tt>''' signal when its value changes, we are here creating a chain of signals and slots.
 </translate>
 <translate>
-=== Running the Application ===
+=== Running the Application === <!--T:24-->
 On startup, the program's appearance is identical to the previous one. Try operating the slider to the bottom-right.
-=== Exercises ===
+=== Exercises === <!--T:26-->
 Use the bottom-right slider to set all LCDs to 50. Then set all but the last LCD to 40 by clicking once to the left of the bottom-middle slider handle. Now, use the bottom-left slider to set the first seven LCDs back to 50.
 Click to the left of the handle on the bottom-right slider. What happens? Why is this the correct behavior?
 [[Category:Ruby]]
 </translate>

@@ Line 18: / Line 18: @@
 <translate>
 Files:
 * [http://www.darshancomputing.com/qt4-qtruby-tutorial/tutorial/t7/lcdrange.rb lcdrange.rb]
 * [http://www.darshancomputing.com/qt4-qtruby-tutorial/tutorial/t7/t7.rb t7.rb]
 <translate>
@@ Line 31: / Line 31: @@
 === Line by Line Walkthrough ===
 </translate>
 '''[http://www.darshancomputing.com/qt4-qtruby-tutorial/tutorial/t7/lcdrange.rb lcdrange.rb]'''
 <translate>
@@ Line 84: / Line 82: @@
 </translate>
 '''[http://www.darshancomputing.com/qt4-qtruby-tutorial/tutorial/t7/t7.rb t7.rb]'''
 <syntaxhighlight lang="ruby">
 previousRange = nil

@@ Line 1: / Line 1: @@
 {{Template:I18n/Language Navigation Bar|Development/Tutorials/Qt4 Ruby Tutorial/Chapter 07}}
-{{TutorialBrowser|
+{{<translate>TutorialBrowser</translate>|
+series=[[Special:myLanguage/Development/Tutorials/Qt4_Ruby_Tutorial|<translate>Qt4 Ruby Tutorial</translate>]]|
-series=[[Development/Tutorials/Qt4_Ruby_Tutorial|Qt4 Ruby Tutorial]]|
+name=<translate>One Thing Leads to Another</translate>|
+pre=[[Special:myLanguage/Development/Tutorials/Qt4_Ruby_Tutorial/Chapter_06|<translate>Tutorial 6 - Building Blocks Galore!</translate>]]|
-name=One Thing Leads to Another|
+next=[[Special:myLanguage/Development/Tutorials/Qt4_Ruby_Tutorial/Chapter_08|<translate>Tutorial 8 - Preparing for Battle</translate>]]
-−
 pre=[[Development/Tutorials/Qt4_Ruby_Tutorial/Chapter_06|Tutorial 6 - Building Blocks Galore!]]|
-−
 next=[[Development/Tutorials/Qt4_Ruby_Tutorial/Chapter_08|Tutorial 8 - Preparing for Battle]]
 }}
 == One Thing Leads to Another ==
 [[Image:Qt4_Ruby_Tutorial_Screenshot_7.png|center]]
 Files:
 * [http://www.darshancomputing.com/qt4-qtruby-tutorial/tutorial/t7/lcdrange.rb lcdrange.rb]
 * [http://www.darshancomputing.com/qt4-qtruby-tutorial/tutorial/t7/t7.rb t7.rb]
 === Overview ===
 This example shows how to create custom widgets with signals and slots, and how to connect them together in more complex ways. For the first time, the source is split among several files.
 === Line by Line Walkthrough ===
 '''[http://www.darshancomputing.com/qt4-qtruby-tutorial/tutorial/t7/lcdrange.rb lcdrange.rb]'''
 This file is mainly lifted from Chapter 6; only the non-trivial changes are noted here.
 <syntaxhighlight lang="ruby">
@@ Line 39: / Line 53: @@
 </syntaxhighlight>
 These make up an interface between this widget and other components in a program. Until now, '''<tt>LCDRange</tt>''' didn't really have an API at all.
@@ Line 50: / Line 65: @@
 The implementation of '''<tt>setValue()</tt>''' is equally straightforward. Note that because the slider and LCD number are connected, setting the slider's value automatically updates the LCD number as well. In addition, the slider will automatically adjust the value if it is outside its legal range.
 <syntaxhighlight lang="ruby">
@@ Line 58: / Line 74: @@
 </syntaxhighlight>
 The first [http://doc.qt.nokia.com/latest/qobject.html#connect QObject::connect()] call is the same that you have seen in the previous chapter. The second is new; it connects slider's [http://doc.qt.nokia.com/latest/qabstractslider.html#valueChanged QAbstractSlider::valueChanged()] signal to this object's '''<tt>valueChanged()</tt>''' signal. Yes, that's right. Signals can be connected to other signals. When the first is emitted, the second signal is also emitted.
@@ Line 65: / Line 82: @@
 Note that you're not guaranteed any particular order of execution; '''<tt>LCDRange::valueChanged()</tt>''' may be emitted before or after [http://doc.qt.nokia.com/latest/qlcdnumber.html#intValue-prop QLCDNumber::display()] is called.
 '''[http://www.darshancomputing.com/qt4-qtruby-tutorial/tutorial/t7/t7.rb t7.rb]'''
 <syntaxhighlight lang="ruby">
 previousRange = nil
@@ Line 83: / Line 103: @@
 </syntaxhighlight>
 When we create the nine '''<tt>LCDRange</tt>''' objects, we connect them using the [http://doc.qt.nokia.com/latest/signalsandslots.html signals and slots] mechanism. Each has its '''<tt>valueChanged()</tt>''' signal connected to the previous one's '''<tt>setValue()</tt>''' slot. Because '''<tt>LCDRange</tt>''' emits the '''<tt>valueChanged()</tt>''' signal when its value changes, we are here creating a chain of signals and slots.
 === Running the Application ===
 On startup, the program's appearance is identical to the previous one. Try operating the slider to the bottom-right.
 === Exercises ===
 Use the bottom-right slider to set all LCDs to 50. Then set all but the last LCD to 40 by clicking once to the left of the bottom-middle slider handle. Now, use the bottom-left slider to set the first seven LCDs back to 50.
@@ Line 94: / Line 119: @@
 [[Category:Ruby]]