Make canvas zoom sliders step by proper increments

Instead of stepping by 1%, which is not particularly useful, they now
use the same increments as the zoom in/out action and mouse wheel.

ChangeLog

@@ -49,6 +49,7 @@ Unreleased Version 2.2.2-pre
  * Feature: Always show drawing tools toolbar in small screen mode. Thanks Blozzom for suggesting.
  * Fix: Increase contrast on depressed buttons in dark themes. This is a patch to Qt. Thanks MorrowShore for reporting.
  * Fix: Switch out the icon for the extension buttons on squashed menus and toolbars so that they're actually visible in dark themes. This is a patch to Qt.
+ * Feature: Make canvas zoom slider use the same increments as the mouse wheel and zoom in/out actions, since stepping by 1% is not useful. Thanks zheida for suggesting.
 
 2024-02-25 Version 2.2.2-beta.1
  * Server Feature: Allow adding a message when kicking someone through the admin API.

src/desktop/CMakeLists.txt

@@ -384,6 +384,8 @@ target_sources(drawpile PRIVATE
 	widgets/viewstatus.h
 	widgets/viewstatusbar.cpp
 	widgets/viewstatusbar.h
+	widgets/zoomslider.cpp
+	widgets/zoomslider.h
 )
 
 target_link_libraries(drawpile PRIVATE

src/desktop/docks/navigator.cpp

@@ -3,7 +3,7 @@
 #include "desktop/docks/navigator.h"
 #include "desktop/main.h"
 #include "desktop/widgets/groupedtoolbutton.h"
-#include "desktop/widgets/kis_slider_spin_box.h"
+#include "desktop/widgets/zoomslider.h"
 #include "libclient/canvas/canvasmodel.h"
 #include "libclient/canvas/paintengine.h"
 #include "libclient/canvas/userlist.h"
@@ -486,7 +486,7 @@ Navigator::Navigator(QWidget *parent)
 	m_resetZoomButton->setIcon(QIcon::fromTheme("zoom-original"));
 	titlebar->addCustomWidget(m_resetZoomButton);
 
-	m_zoomSlider = new KisDoubleSliderSpinBox{this};
+	m_zoomSlider = new widgets::ZoomSlider(this);
 	m_zoomSlider->setMinimumWidth(0);
 	m_zoomSlider->setSizePolicy(QSizePolicy(QSizePolicy::Expanding, QSizePolicy::Minimum));
 	m_zoomSlider->setMinimum(zoomMin * 100.0);
@@ -501,6 +501,9 @@ Navigator::Navigator(QWidget *parent)
 	connect(m_view, &NavigatorView::wheelZoom, this, &Navigator::wheelZoom);
 	connect(m_resetZoomButton, &widgets::GroupedToolButton::clicked, this, [this] { emit zoomChanged(1.0); });
 	connect(m_zoomSlider, QOverload<double>::of(&KisDoubleSliderSpinBox::valueChanged), this, &Navigator::updateZoom);
+	connect(
+		m_zoomSlider, &widgets::ZoomSlider::zoomStepped, this,
+		&Navigator::wheelZoom, Qt::QueuedConnection);
 
 	QAction *showCursorsAction = new QAction(tr("Show Cursors"), m_view);
 	showCursorsAction->setCheckable(true);

src/desktop/docks/navigator.h

@@ -5,7 +5,6 @@
 
 #include "desktop/docks/dockbase.h"
 
-class KisDoubleSliderSpinBox;
 class QMenu;
 
 namespace canvas {
@@ -15,6 +14,7 @@ class PaintEngine;
 
 namespace widgets{
 class GroupedToolButton;
+class ZoomSlider;
 }
 
 namespace docks {
@@ -114,7 +114,7 @@ private slots:
 	void zoomChanged(qreal newZoom);
 
 private:
-	KisDoubleSliderSpinBox *m_zoomSlider;
+	widgets::ZoomSlider *m_zoomSlider;
 	widgets::GroupedToolButton *m_resetZoomButton;
 	NavigatorView *m_view;
 	bool m_updating;

src/desktop/scene/scenewrapper.cpp

@@ -398,6 +398,9 @@ void SceneWrapper::connectViewStatus(widgets::ViewStatus *viewStatus)
 	connect(
 		m_view, &CanvasView::viewTransformed, viewStatus,
 		&widgets::ViewStatus::setTransformation);
+	connect(
+		viewStatus, &widgets::ViewStatus::zoomStepped, m_view,
+		&CanvasView::zoomSteps);
 	connect(
 		viewStatus, &widgets::ViewStatus::zoomChanged, m_view,
 		&CanvasView::setZoom);

src/desktop/view/viewwrapper.cpp

@@ -397,6 +397,9 @@ void ViewWrapper::connectViewStatus(widgets::ViewStatus *viewStatus)
 	connect(
 		m_controller, &CanvasController::transformChanged, viewStatus,
 		&widgets::ViewStatus::setTransformation);
+	connect(
+		viewStatus, &widgets::ViewStatus::zoomStepped, m_controller,
+		&CanvasController::zoomSteps);
 	connect(
 		viewStatus, &widgets::ViewStatus::zoomChanged, m_controller,
 		&CanvasController::setZoom);

src/desktop/widgets/kis_double_parse_spin_box.h

@@ -32,7 +32,7 @@ class KisDoubleParseSpinBox : public QDoubleSpinBox
      * uses @ref setValue
      * @param steps Number of steps that the value should change
      */
-    void stepBy(int steps) final override;
+    void stepBy(int steps) override;
     /**
      * @brief Set the value of the spinbox
      *

src/desktop/widgets/kis_int_parse_spin_box.h

@@ -32,7 +32,7 @@ class KisIntParseSpinBox : public QSpinBox
      * uses @ref setValue
      * @param steps Number of steps that the value should change
      */
-    void stepBy(int steps) final override;
+    void stepBy(int steps) override;
     /**
      * @brief Set the value of the spinbox
      *

src/desktop/widgets/kis_slider_spin_box.h

@@ -45,7 +45,7 @@ class KisSliderSpinBoxPrivate;
  * The "soft range" is considered valid if the "soft maximum" is greater than
  * the "soft minimum".
  */
-class KisSliderSpinBox final : public KisIntParseSpinBox
+class KisSliderSpinBox : public KisIntParseSpinBox
 {
     Q_OBJECT
 public:
@@ -206,7 +206,7 @@ class KisSliderSpinBox final : public KisIntParseSpinBox
  *
  * @see KisSliderSpinBox
  */
-class KisDoubleSliderSpinBox final : public KisDoubleParseSpinBox
+class KisDoubleSliderSpinBox : public KisDoubleParseSpinBox
 {
     Q_OBJECT
 public:

src/desktop/widgets/viewstatus.cpp

@@ -4,6 +4,7 @@
 #include "desktop/widgets/groupedtoolbutton.h"
 #include "desktop/widgets/kis_slider_spin_box.h"
 #include "desktop/widgets/KisAngleGauge.h"
+#include "desktop/widgets/zoomslider.h"
 #include "libclient/settings.h"
 #include "libshared/util/qtcompat.h"
 
@@ -95,7 +96,7 @@ ViewStatus::ViewStatus(QWidget *parent)
 	layout->addWidget(m_angleBox);
 
 	// Zoom slider
-	m_zoomSlider = new KisDoubleSliderSpinBox{this};
+	m_zoomSlider = new ZoomSlider(this);
 	m_zoomSlider->setMinimumWidth(24);
 	m_zoomSlider->setMaximumWidth(200);
 	m_zoomSlider->setSizePolicy(QSizePolicy(QSizePolicy::Expanding, QSizePolicy::Minimum));
@@ -105,6 +106,9 @@ ViewStatus::ViewStatus(QWidget *parent)
 	m_zoomSlider->setValue(100.0);
 	m_zoomSlider->setSuffix("%");
 	connect(m_zoomSlider, QOverload<double>::of(&KisDoubleSliderSpinBox::valueChanged), this, &ViewStatus::zoomSliderChanged);
+	connect(
+		m_zoomSlider, &ZoomSlider::zoomStepped, this, &ViewStatus::zoomStepped,
+		Qt::QueuedConnection);
 
 	// Zoom preset button
 	m_zoomPreset = new widgets::GroupedToolButton(this);

src/desktop/widgets/viewstatus.h

@@ -5,14 +5,14 @@
 
 #include <QWidget>
 
-class KisDoubleSliderSpinBox;
 class QComboBox;
 class QMenu;
 
 namespace widgets {
 
 class GroupedToolButton;
 class KisAngleGauge;
+class ZoomSlider;
 
 class ViewStatus final : public QWidget
 {
@@ -28,6 +28,7 @@ public slots:
 	void setTransformation(qreal zoom, qreal angle);
 
 signals:
+	void zoomStepped(int steps);
 	void zoomChanged(qreal newZoom);
 	void angleChanged(qreal newAngle);
 
@@ -41,7 +42,7 @@ private slots:
 private:
 	void updatePalette();
 
-	KisDoubleSliderSpinBox *m_zoomSlider;
+	ZoomSlider *m_zoomSlider;
 	KisAngleGauge *m_compass;
 	QComboBox *m_angleBox;
 	bool m_updating;

src/desktop/widgets/zoomslider.cpp

@@ -0,0 +1,17 @@
+#include "desktop/widgets/zoomslider.h"
+
+namespace widgets {
+
+ZoomSlider::ZoomSlider(QWidget *parent)
+	: KisDoubleSliderSpinBox(parent)
+{
+}
+
+void ZoomSlider::stepBy(int steps)
+{
+	if(steps != 0) {
+		emit zoomStepped(steps);
+	}
+}
+
+}

src/desktop/widgets/zoomslider.h

@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+#include "desktop/widgets/kis_slider_spin_box.h"
+
+namespace widgets {
+
+class ZoomSlider : public KisDoubleSliderSpinBox {
+	Q_OBJECT
+public:
+	ZoomSlider(QWidget *parent);
+
+	void stepBy(int steps) override;
+
+signals:
+	void zoomStepped(int steps);
+};
+
+}