From 89773cc69c625174c4b07aa9938e4382822bdc05 Mon Sep 17 00:00:00 2001
From: Ivailo Monev <xakepa10@gmail.com>
Date: Mon, 6 May 2024 01:20:43 +0300
Subject: [PATCH] plasma: implement number increment/decrement on mouse wheel
 event for calculator applet

Signed-off-by: Ivailo Monev <xakepa10@gmail.com>
---
 plasma/applets/calculator/calculator.cpp | 28 ++++++++++++++++++------
 plasma/applets/calculator/calculator.h   |  4 +++-
 2 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/plasma/applets/calculator/calculator.cpp b/plasma/applets/calculator/calculator.cpp
index 499c3237..757fad40 100644
--- a/plasma/applets/calculator/calculator.cpp
+++ b/plasma/applets/calculator/calculator.cpp
@@ -28,11 +28,12 @@
 
 static const QString s_decimal = QString::fromLatin1(".");
 static const QLatin1String s_zero = QLatin1String("0");
+// hard-limit
+static const int s_limit = 6;
 
-static QString kAddNumber(const QString &string, const ushort number)
+static QString kAddNumber(const QString &string, const short number)
 {
-    if (string.size() > 6) {
-        // hard-limit
+    if (string.size() > s_limit) {
         return string;
     }
     if (string == s_zero) {
@@ -63,6 +64,8 @@ public:
 
     CalculatorAppletWidget(QGraphicsWidget *parent);
 
+    void addToNumber(const short number);
+
 public Q_SLOTS:
     void slotClear();
     void slotDiv();
@@ -294,6 +297,11 @@ CalculatorAppletWidget::CalculatorAppletWidget(QGraphicsWidget *parent)
     );
 }
 
+void CalculatorAppletWidget::addToNumber(const short number)
+{
+    m_label->setText(QString::number(m_label->text().toFloat() + number));
+}
+
 void CalculatorAppletWidget::slotClear()
 {
     m_label->setText(QString::fromLatin1("0"));
@@ -466,10 +474,6 @@ QGraphicsWidget* CalculatorApplet::graphicsWidget()
     return m_calculatorwidget;
 }
 
-// TODO: two ideas come into mind:
-// 1. increment/decrement the number on mouse wheel event
-// 2. instead of calling slots directly trigger buttons press and then release as indicator why the
-// number changed (even tho it will happen very quickly)
 void CalculatorApplet::keyPressEvent(QKeyEvent *event)
 {
     bool eventhandled = false;
@@ -577,5 +581,15 @@ void CalculatorApplet::keyPressEvent(QKeyEvent *event)
     }
 }
 
+void CalculatorApplet::wheelEvent(QGraphicsSceneWheelEvent *event)
+{
+    event->ignore();
+    if (event->delta() > 0) {
+        m_calculatorwidget->addToNumber(1);
+    } else {
+        m_calculatorwidget->addToNumber(-1);
+    }
+}
+
 #include "moc_calculator.cpp"
 #include "calculator.moc"
diff --git a/plasma/applets/calculator/calculator.h b/plasma/applets/calculator/calculator.h
index b17b62b4..78774888 100644
--- a/plasma/applets/calculator/calculator.h
+++ b/plasma/applets/calculator/calculator.h
@@ -19,6 +19,7 @@
 #ifndef CALCULATOR_H
 #define CALCULATOR_H
 
+#include <QGraphicsSceneWheelEvent>
 #include <Plasma/PopupApplet>
 
 class CalculatorAppletWidget;
@@ -34,8 +35,9 @@ public:
     QGraphicsWidget* graphicsWidget() final;
 
 protected:
-    // QGraphicsWidget reimplementation
+    // QGraphicsWidget reimplementations
     void keyPressEvent(QKeyEvent *event) final;
+    void wheelEvent(QGraphicsSceneWheelEvent *event) final;
 
 private:
     friend CalculatorAppletWidget;