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1 <?xml version="1.0" encoding="utf-8"?> |
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2 <!-- Copyright (c) 2007-2010 Nokia Corporation and/or its subsidiary(-ies) All rights reserved. --> |
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3 <!-- This component and the accompanying materials are made available under the terms of the License |
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4 "Eclipse Public License v1.0" which accompanies this distribution, |
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5 and is available at the URL "http://www.eclipse.org/legal/epl-v10.html". --> |
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6 <!-- Initial Contributors: |
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7 Nokia Corporation - initial contribution. |
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8 Contributors: |
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9 --> |
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10 <!DOCTYPE concept |
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11 PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd"> |
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12 <concept id="GUID-57CA8A13-05C6-4AFE-9804-E2EA2453143A" xml:lang="en"><title>Compound |
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13 controls in the view architecture</title><prolog><metadata><keywords/></metadata></prolog><conbody> |
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14 <p><xref href="GUID-352850A9-227F-45DB-8DCD-C6268954B4ED.dita">Compound controls</xref> are |
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15 controls that contain other controls. To create a compound control, you must |
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16 do the following:</p> |
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17 <ul> |
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18 <li><p>construct the control in the parent control, which is the |
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19 control that owns the window in which the control appears. The control should |
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20 be constructed in the constructor for the window. An example of an implementation |
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21 is as follows:</p> |
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22 <itemgroup> |
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23 <codeblock id="GUID-87D5DA2C-DF12-40CA-8F39-CA9B61500F8F" xml:space="preserve">void CMyViewContainer::ConstructL(const TRect& aRect) |
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24 { |
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25 CreateWindowL(); |
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26 |
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27 iLabel = new (ELeave) CEikLabel; |
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28 iLabel->SetContainerWindowL( *this ); |
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29 iLabel->SetTextL( _L("MyView 1\n\nSelect local view\nswitching from menu") ); |
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30 |
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31 SetRect(aRect); |
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32 ActivateL(); |
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33 }</codeblock> |
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34 <p>, where</p> |
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35 <p><parmname>iLabel = new (ELeave) CEikLabel;</parmname> creates a <xref href="jar:GUID-759FBC7F-5384-4487-8457-A8D4B76F6AA6.jar!/html/classCEikLabel.html" format="application/java-archive"><parmname>CEikLabel</parmname></xref> object, |
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36 which is a class that supports the display of text in the parent window.</p> |
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37 <p><xref href="jar:GUID-35228542-8C95-4849-A73F-2B4F082F0C44.jar!/sdk/doc_source/reference/reference-cpp/Control_Environment/CCoeControlClass.html#%3a%3aCCoeControl%3a%3aSetContainerWindowL%28const%20CCoeControl%20%26amp%3b%29" format="application/java-archive"><parmname>CCoeControl::SetContainerWindowL</parmname></xref> assigns |
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38 the non-window-owning control to the window-owning control</p> |
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39 <p><xref href="jar:GUID-759FBC7F-5384-4487-8457-A8D4B76F6AA6.jar!/html/classCEikLabel.html#bcf1d51ebf4177465387f76584078f0c" format="application/java-archive"><parmname>CEikLabel::SetTextL</parmname></xref> sets a text for the label.</p> |
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40 <p>The other methods are the standard methods for creating a window for |
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41 the window-owning control.</p> |
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42 </itemgroup> |
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43 </li> |
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44 <li><p>add a method to the owning control that returns the number |
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45 of controls in the compound control. An example of an implementation is as |
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46 follows:</p> |
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47 <itemgroup> |
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48 <codeblock id="GUID-048B5DCE-124A-4530-89AD-842DCA2F3FFC" xml:space="preserve">TInt CMyViewAppContainer::CountComponentControls() const |
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49 { |
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50 return KNumberOfControls; // return nbr of controls inside this compound control |
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51 }</codeblock> |
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52 <p>, where</p> |
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53 <p><parmname>CMyViewAppContainer::CountComponentControls()</parmname> overrides <xref href="jar:GUID-35228542-8C95-4849-A73F-2B4F082F0C44.jar!/sdk/doc_source/reference/reference-cpp/Control_Environment/CCoeControlClass.html#%3a%3aCCoeControl%3a%3aCountComponentControls%28%29const" format="application/java-archive"><parmname>CCoeControl::CountComponentControls</parmname></xref> to |
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54 return the number of controls in the compound control.</p> |
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55 <p><parmname>KNumberOfControls</parmname> is a <parmname>TInt</parmname> constant |
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56 for the number of controls in the application. Other approaches could be used.</p> |
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57 </itemgroup> |
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58 </li> |
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59 <li><p>Add a method to the owning control that returns each of the |
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60 controls by a zero-based index. An example of an implementation is as follows:</p> |
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61 <itemgroup> |
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62 <codeblock id="GUID-3A8A5312-117E-466F-A5BC-6B7AF0A75B9C" xml:space="preserve">CCoeControl* CContainerContainer::ComponentControl( |
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63 TInt aIndex) const |
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64 { |
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65 switch ( aIndex ) |
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66 { |
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67 case 0: |
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68 return iLabel; // return a pointer to the |
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69 //iLabel |
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70 default: |
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71 return NULL; |
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72 } |
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73 } |
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74 </codeblock> |
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75 <p>, where</p> |
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76 <p><parmname>CCoeControl* CContainerContainer::ComponentControl(TInt aIndex)</parmname> gets |
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77 an indexed component of a compound control. There are 2 ways to implement |
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78 a compound control. One way is to override this function. The other way is |
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79 to use the <xref href="jar:GUID-35228542-8C95-4849-A73F-2B4F082F0C44.jar!/sdk/doc_source/reference/reference-cpp/Control_Environment/CCoeControlArrayClass.html#_top%20title=" format="application/java-archive"><parmname>CCoeControlArray</parmname></xref> functionality (see the <xref href="jar:GUID-35228542-8C95-4849-A73F-2B4F082F0C44.jar!/sdk/doc_source/reference/reference-cpp/Control_Environment/CCoeControlClass.html#%3a%3aCCoeControl%3a%3aInitComponentArrayL%28%29" format="application/java-archive"><parmname>CCoeControl::InitComponentArrayL</parmname></xref> method). |
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80 Note: within a compound control, each component control is identified by |
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81 an index, where the index depends on the order the controls were added: the |
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82 first is given an index of <parmname>0</parmname>, the next an index of <parmname>1</parmname>, |
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83 and so on. </p> |
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84 <p>All child controls should be accessible by <xref href="jar:GUID-35228542-8C95-4849-A73F-2B4F082F0C44.jar!/sdk/doc_source/reference/reference-cpp/Control_Environment/CCoeControlClass.html#%3a%3aCCoeControl%3a%3aComponentControl%28TInt%29const" format="application/java-archive"><parmname>CCoeControl::ComponentControl</parmname></xref> at any time, regardless |
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85 of whether they are visible or not. The visibility of a control should be |
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86 adjusted using the <xref href="jar:GUID-35228542-8C95-4849-A73F-2B4F082F0C44.jar!/sdk/doc_source/reference/reference-cpp/Control_Environment/CCoeControlClass.html#%3a%3aCCoeControl%3a%3aMakeVisible%28TBool%29" format="application/java-archive"><parmname>CCoeControl::MakeVisible</parmname></xref> method.</p> |
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87 </itemgroup> |
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88 </li> |
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89 </ul> |
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90 <p><parmname>CCoeControl* CContainerContainer::ComponentControl(TInt aIndex)</parmname> and <xref href="jar:GUID-35228542-8C95-4849-A73F-2B4F082F0C44.jar!/sdk/doc_source/reference/reference-cpp/Control_Environment/CCoeControlClass.html#%3a%3aCCoeControl%3a%3aCountComponentControls%28%29const" format="application/java-archive"><parmname>CCoeControl::CountComponentControls</parmname></xref> work |
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91 in conjunction with each other. The Symbian platform can query the control |
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92 as to how many components it has and then request a pointer to each of the |
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93 component's controls. Controls can be added or removed at run time using these |
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94 two methods. The framework uses this information to draw the container. </p> |
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95 <p>The compound control usually owns the child controls and therefore it |
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96 is responsible of their construction and destruction. The compound control |
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97 should also set the positions and sizes of its child controls; it must ensure |
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98 that all child controls are inside the compound control rectangle and visible |
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99 child rectangles do not overlap each other.</p> |
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100 </conbody></concept> |