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MKleusbergMKleusberg
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Add zooming to image viewer in the Edit Dialog
This adds some basic zooming functionality to the image viewer used in the Edit Dialog. See issue #2029.
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5 files changed

+149
-4
lines changed

5 files changed

+149
-4
lines changed

‎src/ImageViewer.cpp‎

Lines changed: 38 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -4,12 +4,14 @@
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#include <QPrinter>
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#include <QPrintPreviewDialog>
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#include <QPainter>
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#include <QScrollBar>
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ImageViewer::ImageViewer(QWidget* parent) :
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QWidget(parent),
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ui(new Ui::ImageViewer)
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{
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ui->setupUi(this);
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connect(ui->buttonOriginalSize, &QToolButton::clicked, [this]{ scaleImage(100); });
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ui->labelView->addAction(ui->actionPrintImage);
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}
@@ -27,6 +29,9 @@ void ImageViewer::resetImage()
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void ImageViewer::setImage(const QImage& image)
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{
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ui->labelView->setPixmap(QPixmap::fromImage(image));
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// Reset the scaling to show the image in its original size
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scaleImage(100);
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}
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void ImageViewer::openPrintImageDialog()
@@ -46,3 +51,36 @@ void ImageViewer::openPrintImageDialog()
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dialog.exec();
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}
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void ImageViewer::scaleToFitWindow(bool enabled)
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{
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// Enable/disable the automatic resizing of the label inside the scrollbar
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ui->scrollArea->setWidgetResizable(enabled);
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// When disabling the fit to window scaling, revert back to the original image size
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if(!enabled)
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scaleImage(100);
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}
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void ImageViewer::scaleImage(int scale)
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{
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// Make sure the slider is updated when this is called programatically
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ui->sliderScale->setValue(scale);
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// Update our scale factor
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qreal factor_change = (scale / 100.0) / m_scale_factor;
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m_scale_factor = scale / 100.0;
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// Resize the image
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ui->labelView->resize(m_scale_factor * ui->labelView->pixmap()->size());
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// Uncheck the fit to window button
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ui->buttonFitToWindow->setChecked(false);
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// Fix scroll bars to zoom into center of viewport instead of tthe upper left corner
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const auto adjust_scrollbar = [](QScrollBar* scroll_bar, qreal factor) {
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scroll_bar->setValue(static_cast<int>(factor * scroll_bar->value() + ((factor - 1) * scroll_bar->pageStep() / 2)));
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};
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adjust_scrollbar(ui->scrollArea->horizontalScrollBar(), factor_change);
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adjust_scrollbar(ui->scrollArea->verticalScrollBar(), factor_change);
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}

‎src/ImageViewer.h‎

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Original file line numberDiff line numberDiff line change
@@ -21,8 +21,14 @@ class ImageViewer : public QWidget
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public slots:
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void openPrintImageDialog();
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private slots:
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void scaleToFitWindow(bool enabled);
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void scaleImage(int scale);
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private:
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Ui::ImageViewer* ui;
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qreal m_scale_factor;
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};
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#endif

‎src/ImageViewer.ui‎

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@@ -31,24 +31,88 @@
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</property>
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<item>
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<widget class="QScrollArea" name="scrollArea">
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<property name="widgetResizable">
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<bool>true</bool>
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</property>
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<widget class="QLabel" name="labelView">
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<property name="geometry">
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<rect>
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<x>0</x>
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<y>0</y>
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<width>431</width>
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<height>305</height>
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<height>280</height>
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</rect>
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</property>
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<property name="sizePolicy">
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<sizepolicy hsizetype="Ignored" vsizetype="Ignored">
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<horstretch>0</horstretch>
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<verstretch>0</verstretch>
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</sizepolicy>
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</property>
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<property name="contextMenuPolicy">
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<enum>Qt::ActionsContextMenu</enum>
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</property>
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<property name="scaledContents">
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<bool>true</bool>
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</property>
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</widget>
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</widget>
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</item>
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<item>
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<layout class="QHBoxLayout" name="horizontalLayout">
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<item>
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<spacer name="horizontalSpacer">
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<property name="orientation">
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<enum>Qt::Horizontal</enum>
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</property>
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<property name="sizeHint" stdset="0">
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<size>
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<width>40</width>
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<height>20</height>
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</size>
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</property>
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</spacer>
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</item>
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<item>
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<widget class="QSlider" name="sliderScale">
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<property name="minimum">
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<number>1</number>
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</property>
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<property name="maximum">
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<number>800</number>
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</property>
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<property name="value">
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<number>100</number>
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</property>
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<property name="orientation">
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<enum>Qt::Horizontal</enum>
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</property>
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</widget>
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</item>
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<item>
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<widget class="QToolButton" name="buttonOriginalSize">
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<property name="toolTip">
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<string>Reset the scaling to match the original size of the image.</string>
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</property>
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<property name="icon">
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<iconset resource="icons/icons.qrc">
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<normaloff>:/icons/view</normaloff>:/icons/view</iconset>
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</property>
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</widget>
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</item>
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<item>
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<widget class="QToolButton" name="buttonFitToWindow">
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<property name="toolTip">
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<string>Set the scaling to match the size of the viewport.</string>
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</property>
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<property name="icon">
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<iconset resource="icons/icons.qrc">
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<normaloff>:/icons/monitor_link.png</normaloff>:/icons/monitor_link.png</iconset>
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</property>
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<property name="checkable">
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<bool>true</bool>
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</property>
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</widget>
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</item>
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</layout>
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</item>
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</layout>
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<action name="actionPrintImage">
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<property name="icon">
@@ -86,5 +150,41 @@
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</hint>
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</hints>
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</connection>
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<connection>
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<sender>sliderScale</sender>
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<signal>valueChanged(int)</signal>
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<receiver>ImageViewer</receiver>
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<slot>scaleImage(int)</slot>
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<hints>
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<hint type="sourcelabel">
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<x>280</x>
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<y>294</y>
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</hint>
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<hint type="destinationlabel">
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<x>216</x>
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<y>153</y>
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</hint>
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</hints>
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</connection>
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<connection>
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<sender>buttonFitToWindow</sender>
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<signal>toggled(bool)</signal>
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<receiver>ImageViewer</receiver>
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<slot>scaleToFitWindow(bool)</slot>
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<hints>
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<hint type="sourcelabel">
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<x>419</x>
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<y>294</y>
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</hint>
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<hint type="destinationlabel">
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<x>216</x>
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<y>153</y>
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</hint>
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</hints>
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</connection>
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</connections>
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<slots>
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<slot>scaleImage(int)</slot>
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<slot>scaleToFitWindow(bool)</slot>
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</slots>
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</ui>

‎src/icons/icons.qrc‎

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@@ -101,5 +101,6 @@
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<file alias="open_in_app">application_link.png</file>
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<file alias="document_link">document-link.png</file>
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<file alias="open_data_in_app">application_go.png</file>
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<file>monitor_link.png</file>
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</qresource>
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</RCC>

‎src/icons/monitor_link.png‎

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