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MKleusbergMKleusberg
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Delay applying a changed filter value
When changing a filter value delay the application of the new value on the table for a couple of milliseconds. This makes the filter process much smoother for fast typing users working on large tables. See issue #415.
1 parent 9d7efca commit 71b7806

5 files changed

Lines changed: 114 additions & 42 deletions

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‎CMakeLists.txt‎

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@@ -88,6 +88,7 @@ set(SQLB_MOC_HDR
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src/SqlUiLexer.h
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src/FileDialog.h
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src/ColumnDisplayFormatDialog.h
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src/FilterLineEdit.h
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)
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set(SQLB_SRC
@@ -118,6 +119,7 @@ set(SQLB_SRC
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src/SqlUiLexer.cpp
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src/FileDialog.cpp
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src/ColumnDisplayFormatDialog.cpp
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src/FilterLineEdit.cpp
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)
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set(SQLB_FORMS

‎src/FilterLineEdit.cpp‎

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#include "FilterLineEdit.h"
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#include <QTimer>
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#include <QKeyEvent>
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FilterLineEdit::FilterLineEdit(QWidget* parent, QList<FilterLineEdit*>* filters, int columnnum) : QLineEdit(parent), filterList(filters), columnNumber(columnnum)
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{
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setPlaceholderText(tr("Filter"));
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#if QT_VERSION >= QT_VERSION_CHECK(5, 2, 0)
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setClearButtonEnabled(true);
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#endif
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setProperty("column", columnnum); // Store the column number for later use
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// Introduce a timer for delaying the signal triggered whenever the user changes the filter value.
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// The idea here is that the textChanged() event isn't connected to the update filter slot directly anymore
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// but instead there this timer mechanism in between: whenever the user changes the filter the delay timer
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// is (re)started. As soon as the user stops typing the timer has a chance to trigger and call the
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// delayedSignalTimerTriggered() method which then stops the timer and emits the delayed signal.
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delaySignalTimer = new QTimer(this);
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delaySignalTimer->setInterval(300); // This is the milliseconds of not-typing we want to wait before triggering
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connect(this, SIGNAL(textChanged(QString)), delaySignalTimer, SLOT(start()));
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connect(delaySignalTimer, SIGNAL(timeout()), this, SLOT(delayedSignalTimerTriggered()));
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// Immediately emit the delayed filter value changed signal if the user presses the enter or the return key or
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// the line edit widget loses focus
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connect(this, SIGNAL(editingFinished()), this, SLOT(delayedSignalTimerTriggered()));
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}
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void FilterLineEdit::delayedSignalTimerTriggered()
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{
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// Stop the timer first to avoid triggering in intervals
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delaySignalTimer->stop();
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// Emit the delayed signal using the current value
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emit delayedTextChanged(text());
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}
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void FilterLineEdit::keyReleaseEvent(QKeyEvent* event)
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{
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if(event->key() == Qt::Key_Tab)
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{
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if(columnNumber < filterList->size() - 1)
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{
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filterList->at(columnNumber + 1)->setFocus();
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event->accept();
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}
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} else if(event->key() == Qt::Key_Backtab) {
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if(columnNumber > 0)
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{
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filterList->at(columnNumber - 1)->setFocus();
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event->accept();
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}
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}
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}
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void FilterLineEdit::clear()
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{
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// When programatically clearing the line edit's value make sure the effects are applied immediately, i.e.
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// bypass the delayed signal timer
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QLineEdit::clear();
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delayedSignalTimerTriggered();
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}
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void FilterLineEdit::setText(const QString& text)
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{
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// When programatically setting the line edit's value make sure the effects are applied immediately, i.e.
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// bypass the delayed signal timer
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QLineEdit::setText(text);
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delayedSignalTimerTriggered();
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}

‎src/FilterLineEdit.h‎

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#ifndef FILTERLINEEDIT_H
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#define FILTERLINEEDIT_H
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#include <QLineEdit>
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#include <QList>
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class QTimer;
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class QKeyEvent;
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class FilterLineEdit : public QLineEdit
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{
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Q_OBJECT
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public:
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explicit FilterLineEdit(QWidget* parent, QList<FilterLineEdit*>* filters, int columnnum);
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// Override methods for programatically changing the value of the line edit
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void clear();
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void setText(const QString& text);
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private slots:
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void delayedSignalTimerTriggered();
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signals:
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void delayedTextChanged(QString text);
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protected:
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void keyReleaseEvent(QKeyEvent* event);
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private:
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QList<FilterLineEdit*>* filterList;
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int columnNumber;
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QTimer* delaySignalTimer;
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};
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#endif

‎src/FilterTableHeader.cpp‎

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Original file line numberDiff line numberDiff line change
@@ -1,46 +1,8 @@
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#include "FilterTableHeader.h"
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#include "FilterLineEdit.h"
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#include <QLineEdit>
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#include <QTableView>
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#include <QScrollBar>
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#include <QKeyEvent>
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#include <QDebug>
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class FilterLineEdit : public QLineEdit
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{
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public:
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explicit FilterLineEdit(QWidget* parent, QList<FilterLineEdit*>* filters, int columnnum) : QLineEdit(parent), filterList(filters), columnNumber(columnnum)
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{
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setPlaceholderText(tr("Filter"));
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#if QT_VERSION >= QT_VERSION_CHECK(5, 2, 0)
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setClearButtonEnabled(true);
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#endif
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setProperty("column", columnnum); // Store the column number for later use
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}
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protected:
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void keyReleaseEvent(QKeyEvent* event)
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{
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if(event->key() == Qt::Key_Tab)
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{
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if(columnNumber < filterList->size() - 1)
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{
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filterList->at(columnNumber + 1)->setFocus();
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event->accept();
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}
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} else if(event->key() == Qt::Key_Backtab) {
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if(columnNumber > 0)
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{
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filterList->at(columnNumber - 1)->setFocus();
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event->accept();
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}
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}
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}
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private:
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QList<FilterLineEdit*>* filterList;
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int columnNumber;
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};
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FilterTableHeader::FilterTableHeader(QTableView* parent) :
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QHeaderView(Qt::Horizontal, parent)
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l->setVisible(false);
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else
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l->setVisible(true);
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connect(l, SIGNAL(textChanged(QString)), this, SLOT(inputChanged(QString)));
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connect(l, SIGNAL(delayedTextChanged(QString)), this, SLOT(inputChanged(QString)));
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filterWidgets.push_back(l);
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}
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‎src/src.pro‎

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@@ -52,7 +52,8 @@ HEADERS += \
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ExportSqlDialog.h \
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SqlUiLexer.h \
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FileDialog.h \
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ColumnDisplayFormatDialog.h
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ColumnDisplayFormatDialog.h \
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FilterLineEdit.h
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SOURCES += \
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sqlitedb.cpp \
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ExportSqlDialog.cpp \
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SqlUiLexer.cpp \
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FileDialog.cpp \
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ColumnDisplayFormatDialog.cpp
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ColumnDisplayFormatDialog.cpp \
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FilterLineEdit.cpp
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RESOURCES += icons/icons.qrc \
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translations/flags/flags.qrc \

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