Dynamic FOrms

[BalaQT]

hi,
im new to QT programming,
i want to create DYANMIC form based on DATABASE
for ex:
sqlite table contains how many forms to create and size of the form
QT should connect sqlite table and it should create the forms

pls guide me

Bala

[wysota]

So what's the question?

[BalaQT]

wysota> Thnks for replying me
my question is :
i) how to create forms from QT by reading from SQLITE table

following is the code im using to show one window.


#include <QApplication>
#include <QGridLayout>
#include <QPushButton>
#include <QTextBox>
#include <QProcess>
#include "Connection.h"
#include <QtCore/QVariant>

int main(int argc, char *argv[])
{
QApplication app(argc, argv);
QWidget *win1 = new QWidget;
QGridLayout *layout = new QGridLayout;
QPushButton *ClickButton=new QPushButton("Click");
QPushButton *CancelButton=new QPushButton("Cancel");
QObject::connect(ClickButton,SIGNAL(clicked()),&app,SLOT(quit()));
if(!createConnection())
return 1;
QSqlQuery q;
q.exec("SELECT * FROM ConfigTable");
q.next();
win1->setWindowTitle("Window1");
win1->setFixedHeight(q.value(2).toInt());
win1->setFixedWidth(q.value(3).toInt());
layout->addWidget(ClickButton,0,0);
layout->addWidget(CancelButton,0,2);
win1->setLayout(layout);
win1->show();
return app.exec();
}



How to create more than one windows, if the ConfigTable contain 2 or more records?

Thnks
Bala

[wysota]

I don't see a problem... just use a for() loop and in each iteration create a widget, fill it with child widgets and show it. Alternatively you can use QUiLoader if you can afford storing ui files in the database.

[BalaQT]

Sir, thnks for the reply,
i got the logic. but dont know how to do it in QT coding. pls provide me source code with for loop to create child widgets

Thnks
Bala

[wysota]

How can I provide code if I don't know what the database holds?

[BalaQT]

Table Details
Database : SQLITE
Table Name : ConfigTable
Fields :
FormId Numeric
FormName Text
FormHeight Numeric
FormWidth Numeric

ConfigTable location : E:\Bala\Ramana\DynamicForm\DynaBase

connection.h


#ifndef CONNECTION_H
#define CONNECTION_H

#include <QMessageBox>
#include <QSqlDatabase>
#include <QSqlError>
#include <QSqlQuery>

static bool createConnection()
{
QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE");
//db.setDatabaseName(":memory:");
//db.setDatabaseName("e:/BALA/hirola");
db.setDatabaseName("e:/BALA/Ramana/DynamicForm/DynaBase");
if (!db.open()) {
QMessageBox::critical(0, qApp->tr("Cannot open database"),
qApp->tr("Unable to establish a database connection.\n"
"This example needs SQLite support. Please read "
"the Qt SQL driver documentation for information how "
"to build it.\n\n"
"Click Cancel to exit."), QMessageBox::Cancel);
return false;
}


return true;
}
#endif


DynamicTable.Cpp


#include <QApplication>
#include <QGridLayout>
#include <QPushButton>
#include <QProcess>
#include "Connection.h"
#include <QtCore/QVariant>


int main(int argc, char *argv[])
{
QApplication app(argc, argv);
QWidget *win1 = new QWidget;
QGridLayout *layout = new QGridLayout;
QPushButton *ClickButton=new QPushButton("Click");
QPushButton *CancelButton=new QPushButton("Cancel");
QObject::connect(ClickButton,SIGNAL(clicked()),&app,SLOT(quit()));
if(!createConnection())
return 1;
QSqlQuery q;
q.exec("SELECT * FROM ConfigTable");
QString salary;
q.next();
win1->setWindowTitle("Window1");
win1->setFixedHeight(q.value(2).toInt()); //FormHeight
win1->setFixedWidth(q.value(3).toInt()); //FormWidth
layout->addWidget(ClickButton,0,0);
layout->addWidget(CancelButton,0,2);
win1->setLayout(layout);
win1->show();
return app.exec();
}


This is working fine for ONE ROW, ONE WINDOW.
how to create n windows, if n rows are in configtable.

Thnks
Bala

[wysota]

while(q.next()){
QWidget *w = new QWidget;
w->setWindowTitle(...);
w->setWFixedHeight(q.value(2).toInt());
...
w->show();
}

[BalaQT]

Thnks wysota
it solved my problem.
im new to QT. I understand SIMPLE OR BASIC means not easy untill u familiar with it.
i love QT.but im a beginner. so pls consider me,even if i ask any dumb questions.

i)what is the command for position the forms (LEFT AND TOP)?

Thnks
Bala

[numbat]

w->move(x, y);

[BalaQT]

thanks wysota

its working fine, but i have more doubts in this

how can i access the created window's widgets?
for ex:
a form displayed with 2 line edits in it.
createLineedit is the function im using to create a lineedit.

createLineedit() will be called 2 times to create 2 lineedits;

hw can i access the values in it, when i press one pushbutton

the follwing code called frm main.cpp
createLineedit("id")
createLineedit("name");

How to take the values TYPED in id,name line edit ,when the user press Savepushbutton?

pls guide me

[BalaQT]

any experts pls reply me.

My need is i want to create dynamic widgets and dynamic forms..
Im successful in creating dynamic forms and dynamic widgets, but How can i access the widget's value's?

since all widgets have same name, i can able to take the latest value only
how can i access all the values?

pls guide me

Thanks
Bala

[numbat]

If you have saved the widgets in a list you can just access that list:


for (int i = 0; i < list.size(); i++)
qDebug() << list[i].text();

If you haven't saved a list, you can get one from your top-level widget. This will get all line edits which you can then iterate as above.


QList<QLineEdit *> myEdits = parentWidget.findChildren<QLineEdit *>();

[BalaQT]

Thnks nimbut,
Its working.
one more doubt in connecting SIGNALS AND SLOT

For better understanding, i will explain my need.
im creating forms and lineedit,pushbutton,label DYNAMICALLY frm a DB.


void DynamicControls::createPushButton(QString Wstr,QString WTip,int x,int y)
{
pushButton=new QPushButton(Wstr);
pushButton->setToolTip(WTip);
layout->addWidget(pushButton,x,y);
}


This function will be called in CreateDynamicForm shown below:


void DynamicControls::CreateDynamicForm()
{
QSqlQuery q1,q2;
q1.exec("select * from FormMaster where FormVisible=1 order by FormId");
while(q1.next())
{
tableName=q1.value(7).toString();
q2.exec("select * from WidgetMaster where FormId=" + q1.value(0).toString() + " and WVisible=1 order by RowNo,ColumnNo");
while(q2.next())
{
if(q2.value(2).toString()=="lineedit")
{
createLineEdit(q2.value(3).toString(),q2.value(1). toString(),q2.value(6).toInt(),q2.value(7).toInt() );

else if(q2.value(2).toString()=="PushButton")
{
createPushButton(q2.value(3).toString(),q2.value(1 ).toString(),q2.value(6).toInt(),q2.value(7).toInt ());
}
}
}



The CreateDynamicForm will be called in CONSTRUCTOR
i want to know hw to connect signals
ex:
if the created buttons name is SAVE , then my own slot UPDATEtable() has to be called..
how can i do it.

since its dynamic , im getting some err in the following connect
(frankly i dont know how to connect a dynamically created button into CONNECT())
QObject::connect(pushbutton, SIGNAL(clicked()),this,SLOT(updateTable1(IndxValue 1)));

since all the pushbuttons names are same, connect not working properly.

how to create a connect for dynamically created pushbuttons...

Bala

[wysota]

Come on, all the time you are facing strictly C++ issues. We don't teach C++ nor basics of programming here - get a decent book on C++ to learn about pointers.

As for your last problem - you are passing a value to the slot in the connect statement which is forbidden. See the FAQ section of this site.

[BalaQT]

hi,
Thnks wysota, i will surely study on it. but pls help me here.

a)I've managed to create dynamic buttons.
Now I am having a problem with being able to tell which button was pressed. The button objects are created at runtime and they're added to QList. How do I find out which button in the array was clicked?

ex: 5 buttons are created frm DB. (all are having same name pushbutton)
1)new , 2) save 3)del 4)view 5)exit

i want to perform particular actions according to button click.
how can i know which button was clicked?

Any suggestions?

Thnks
Bala

[nish]

what is the need of sending pms if you posted your topic here and getting replies?

there is a function sender() which you can call in a slot to check which object called that slot.

QList<QPushButton *> btns;
void createbuttons()
{
btns<<new QPushButton("abc",this)<<new QPushButton("abc",this)<<new QPushButton("abc",this);
connect all these buttons to a slot myslot();
}

void myslot()
{
QObject* o = sender();
if(o==btns[0]) etc...
}

[wysota]

how can i know which button was clicked?

I'd suggest using QSignalMapper.