Loading ui at runtime

hema · wrote on 26 Aug 2013, 08:24

hi ,

I am using qt 4.8.2 build on mingw on linux .
I have problem loading ui file at run time .I have added ui form to resource file .I get segmentation fault. the following error is displayed
Designer: An error has occurred while reading the UI file at line 1, column 0: Premature end of document.

the following is the code

QUiLoader loader;

QFile file&#40;":/forms/selectiondialog.ui"&#41;;
file.open(QFile::ReadOnly);

QWidget *formWidget = loader.load(&file); // getting segmentation fault 
file.close();

thanks,
hema

SGaist · wrote on 26 Aug 2013, 08:47

Hi and welcome to devnet,

Are you sure that selectiondialog.ui is found ?

hema · wrote on 26 Aug 2013, 10:00

the following is the error is what i am getting

"<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
<class>Dialog</class>
<widget class="QDialog" name="Dialog">
<property name="geometry">
<rect>
<x>0</x>
<y>0</y>
<width>322</width>
<height>189</height>
</rect>
</property>
<property name="windowTitle">
<string>Dialog</string>
</property>
<layout class="QGridLayout" name="gridLayout_2">
<item row="0" column="0" colspan="3">
<layout class="QGridLayout" name="gridLayout">
<item row="0" column="0">
<widget class="QLabel" name="lbl_First">
<property name="text">
<string/>
</property>
</widget>
</item>
<item row="0" column="1">
<widget class="QLabel" name="lbl_Second">
<property name="text">
<string/>
</property>
</widget>
</item>
<item row="1" column="0">
<widget class="QListWidget" name="listWidget_Initial"/>
</item>
<item row="1" column="1">
<widget class="QListWidget" name="listWidget_Final"/>
</item>
</layout>
</item>
<item row="1" column="0">
<spacer name="horizontalSpacer_2">
<property name="orientation">
<enum>Qt::Horizontal</enum>
</property>
<property name="sizeHint" stdset="0">
<size>
<width>65</width>
<height>20</height>
</size>
</property>
</spacer>
</item>
<item row="1" column="1">
<widget class="QDialogButtonBox" name="buttonBox">
<property name="orientation">
<enum>Qt::Horizontal</enum>
</property>
<property name="standardButtons">
<set>QDialogButtonBox::Cancel|QDialogButtonBox::Ok</set>
</property>
</widget>
</item>
<item row="1" column="2">
<spacer name="horizontalSpacer">
<property name="orientation">
<enum>Qt::Horizontal</enum>
</property>
<property name="sizeHint" stdset="0">
<size>
<width>65</width>
<height>20</height>
</size>
</property>
</spacer>
</item>
</layout>
</widget>
<resources/>
<connections>
<connection>
<sender>buttonBox</sender>
<signal>accepted()</signal>
<receiver>Dialog</receiver>
<slot>accept()</slot>
<hints>
<hint type="sourcelabel">
<x>248</x>
<y>254</y>
</hint>
<hint type="destinationlabel">
<x>157</x>
<y>274</y>
</hint>
</hints>
</connection>
<connection>
<sender>buttonBox</sender>
<signal>rejected()</signal>
<receiver>Dialog</receiver>
<slot>reject()</slot>
<hints>
<hint type="sourcelabel">
<x>316</x>
<y>260</y>
</hint>
<hint type="destinationlabel">
<x>286</x>
<y>274</y>
</hint>
</hints>
</connection>
</connections>
</ui>
"
Designer: An error has occurred while reading the UI file at line 1, column 0: Premature end of document.

SGaist · wrote on 26 Aug 2013, 10:07

Please enclose you code within coding tags so it will make it readable.

I didn't state that the xml was wrong (it should not if you have generated it with designer) but did you check that file.open returns true ?

hema · wrote on 26 Aug 2013, 10:36

selectiondialog.ui
file exists in the forms

hema · wrote on 26 Aug 2013, 11:06

K , but file.open is returing true

SGaist · wrote on 26 Aug 2013, 11:34

Ok then, did you create the ui file yourself ?

hema · wrote on 27 Aug 2013, 05:02

sorry for a long delay ,
this ui is created by myself
I am calling this ui in one function funcn()
funcn()
{
QFile file(":/forms/selectiondialog.ui");
QWidget *selectionWidget = this->loadUiFile(file);
}

QWidget* OptimaRTools::loadUiFile(QFile& file1)
{

QUiLoader loader;
 QFile file&#40;":/forms/selectiondialog.ui"&#41;;
file.open(QFile::ReadOnly);
file.errorString();
QWidget *formWidget = loader.load(&file);
file.close();

return formWidget;
}

and the ui file is

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
<class>Dialog</class>
<widget class="QDialog" name="Dialog">
<property name="geometry">
<rect>
<x>0</x>
<y>0</y>
<width>322</width>
<height>189</height>
</rect>
</property>
<property name="windowTitle">
<string>Dialog</string>
</property>
<layout class="QGridLayout" name="gridLayout_2">
<item row="0" column="0" colspan="3">
<layout class="QGridLayout" name="gridLayout">
<item row="0" column="0">
<widget class="QLabel" name="lbl_First">
<property name="text">
<string/>
</property>
</widget>
</item>
<item row="0" column="1">
<widget class="QLabel" name="lbl_Second">
<property name="text">
<string/>
</property>
</widget>
</item>
<item row="1" column="0">
<widget class="QListWidget" name="listWidget_Initial"/>
</item>
<item row="1" column="1">
<widget class="QListWidget" name="listWidget_Final"/>
</item>
</layout>
</item>
<item row="1" column="0">
<spacer name="horizontalSpacer_2">
<property name="orientation">
<enum>Qt::Horizontal</enum>
</property>
<property name="sizeHint" stdset="0">
<size>
<width>65</width>
<height>20</height>
</size>
</property>
</spacer>
</item>
<item row="1" column="1">
<widget class="QDialogButtonBox" name="buttonBox">
<property name="orientation">
<enum>Qt::Horizontal</enum>
</property>
<property name="standardButtons">
<set>QDialogButtonBox::Cancel|QDialogButtonBox::Ok</set>
</property>
</widget>
</item>
<item row="1" column="2">
<spacer name="horizontalSpacer">
<property name="orientation">
<enum>Qt::Horizontal</enum>
</property>
<property name="sizeHint" stdset="0">
<size>
<width>65</width>
<height>20</height>
</size>
</property>
</spacer>
</item>
</layout>
</widget>
<resources/>
<connections>
<connection>
<sender>buttonBox</sender>
<signal>accepted()</signal>
<receiver>Dialog</receiver>
<slot>accept()</slot>
<hints>
<hint type="sourcelabel">
<x>248</x>
<y>254</y>
</hint>
<hint type="destinationlabel">
<x>157</x>
<y>274</y>
</hint>
</hints>
</connection>
<connection>
<sender>buttonBox</sender>
<signal>rejected()</signal>
<receiver>Dialog</receiver>
<slot>reject()</slot>
<hints>
<hint type="sourcelabel">
<x>316</x>
<y>260</y>
</hint>
<hint type="destinationlabel">
<x>286</x>
<y>274</y>
</hint>
</hints>"
</connection>
</connections>
</ui>

SGaist · wrote on 27 Aug 2013, 07:24

Please use coding tags

What do you mean by yourself ? Using the designer integrated with QtCreator ?

hema · wrote on 27 Aug 2013, 07:33

ui is created using Qt designer form

hema · wrote on 27 Aug 2013, 07:37

@<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
<class>Dialog</class>
<widget class="QDialog" name="Dialog">
<property name="geometry">
<rect>
<x>0</x>
<y>0</y>
<width>322</width>
<height>221</height>
</rect>
</property>
<property name="windowTitle">
<string>Dialog</string>
</property>
<widget class="QDialogButtonBox" name="buttonBox">
<property name="geometry">
<rect>
<x>65</x>
<y>187</y>
<width>181</width>
<height>32</height>
</rect>
</property>
<property name="orientation">
<enum>Qt::Horizontal</enum>
</property>
<property name="standardButtons">
<set>QDialogButtonBox::Cancel|QDialogButtonBox::Ok</set>
</property>
</widget>
<widget class="QWidget" name="layoutWidget">
<property name="geometry">
<rect>
<x>10</x>
<y>10</y>
<width>301</width>
<height>171</height>
</rect>
</property>
<layout class="QGridLayout" name="gridLayout">
<item row="0" column="0">
<widget class="QLabel" name="lbl_First">
<property name="text">
<string/>
</property>
</widget>
</item>
<item row="0" column="1">
<widget class="QLabel" name="lbl_Second">
<property name="text">
<string/>
</property>
</widget>
</item>
<item row="1" column="0">
<widget class="QListWidget" name="listWidget_Initial"/>
</item>
<item row="1" column="1">
<widget class="QListWidget" name="listWidget_Final"/>
</item>
</layout>
</widget>
</widget>
<resources/>
<connections>
<connection>
<sender>buttonBox</sender>
<signal>accepted()</signal>
<receiver>Dialog</receiver>
<slot>accept()</slot>
<hints>
<hint type="sourcelabel">
<x>248</x>
<y>254</y>
</hint>
<hint type="destinationlabel">
<x>157</x>
<y>274</y>
</hint>
</hints>
</connection>
<connection>
<sender>buttonBox</sender>
<signal>rejected()</signal>
<receiver>Dialog</receiver>
<slot>reject()</slot>
<hints>
<hint type="sourcelabel">
<x>316</x>
<y>260</y>
</hint>
<hint type="destinationlabel">
<x>286</x>
<y>274</y>
</hint>
</hints>
</connection>
</connections>
</ui>
@

SGaist · wrote on 27 Aug 2013, 07:40

What does print:

@qDebug() << file.readAll();@

?

hema · wrote on 27 Aug 2013, 07:51

@"<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
<class>Dialog</class>
<widget class="QDialog" name="Dialog">
<property name="geometry">
<rect>
<x>0</x>
<y>0</y>
<width>322</width>
<height>189</height>
</rect>
</property>
<property name="windowTitle">
<string>Dialog</string>
</property>
<layout class="QGridLayout" name="gridLayout_2">
<item row="0" column="0" colspan="3">
<layout class="QGridLayout" name="gridLayout">
<item row="0" column="0">
<widget class="QLabel" name="lbl_First">
<property name="text">
<string/>
</property>
</widget>
</item>
<item row="0" column="1">
<widget class="QLabel" name="lbl_Second">
<property name="text">
<string/>
</property>
</widget>
</item>
<item row="1" column="0">
<widget class="QListWidget" name="listWidget_Initial"/>
</item>
<item row="1" column="1">
<widget class="QListWidget" name="listWidget_Final"/>
</item>
</layout>
</item>
<item row="1" column="0">
<spacer name="horizontalSpacer_2">
<property name="orientation">
<enum>Qt::Horizontal</enum>
</property>
<property name="sizeHint" stdset="0">
<size>
<width>65</width>
<height>20</height>
</size>
</property>
</spacer>
</item>
<item row="1" column="1">
<widget class="QDialogButtonBox" name="buttonBox">
<property name="orientation">
<enum>Qt::Horizontal</enum>
</property>
<property name="standardButtons">
<set>QDialogButtonBox::Cancel|QDialogButtonBox::Ok</set>
</property>
</widget>
</item>
<item row="1" column="2">
<spacer name="horizontalSpacer">
<property name="orientation">
<enum>Qt::Horizontal</enum>
</property>
<property name="sizeHint" stdset="0">
<size>
<width>65</width>
<height>20</height>
</size>
</property>
</spacer>
</item>
</layout>
</widget>
<resources/>
<connections>
<connection>
<sender>buttonBox</sender>
<signal>accepted()</signal>
<receiver>Dialog</receiver>
<slot>accept()</slot>
<hints>
<hint type="sourcelabel">
<x>248</x>
<y>254</y>
</hint>
<hint type="destinationlabel">
<x>157</x>
<y>274</y>
</hint>
</hints>
</connection>
<connection>
<sender>buttonBox</sender>
<signal>rejected()</signal>
<receiver>Dialog</receiver>
<slot>reject()</slot>
<hints>
<hint type="sourcelabel">
<x>316</x>
<y>260</y>
</hint>
<hint type="destinationlabel">
<x>286</x>
<y>274</y>
</hint>
</hints>
</connection>
</connections>
</ui>
"
Designer: An error has occurred while reading the UI file at line 1, column 0: Premature end of document.
"Phonon::SeekSlider" @

SGaist · wrote on 27 Aug 2013, 08:10

Really strange...

Could you try to run the Calculator builder example ? To see if it also has the same problem

hema · wrote on 27 Aug 2013, 08:19

I have tried calculator builder and text finder examples they are working fine

SGaist · wrote on 27 Aug 2013, 08:32

Then copy the ui file from the example in your project and try to load to see if it works also there

hema · wrote on 27 Aug 2013, 10:08

@"<ui version="4.0" >
<author></author>
<comment></comment>
<exportmacro></exportmacro>
<class>CalculatorForm</class>
<widget class="QWidget" name="CalculatorForm" >
<property name="objectName" >
<string notr="true" >CalculatorForm</string>
</property>
<property name="geometry" >
<rect>
<x>0</x>
<y>0</y>
<width>276</width>
<height>98</height>
</rect>
</property>
<property name="sizePolicy" >
<sizepolicy>
<hsizetype>5</hsizetype>
<vsizetype>5</vsizetype>
<horstretch>0</horstretch>
<verstretch>0</verstretch>
</sizepolicy>
</property>
<property name="windowTitle" >
<string>Calculator Builder</string>
</property>
<layout class="QGridLayout" >
<property name="objectName" >
<string notr="true" />
</property>
<property name="margin" >
<number>9</number>
</property>
<property name="spacing" >
<number>6</number>
</property>
<item row="0" column="0" >
<layout class="QHBoxLayout" >
<property name="objectName" >
<string notr="true" />
</property>
<property name="margin" >
<number>1</number>

hema · wrote on 27 Aug 2013, 10:16

loading calculator.ui giving the same error in my application

SGaist · wrote on 27 Aug 2013, 10:25

Then can you post your pro file and a minimal code example that reproduce the problem ?