refactor: buttons and friends (#6102)

src/widgets/buttons/SvgButton.hpp

@@ -0,0 +1,70 @@
+#pragma once
+
+#include "widgets/buttons/Button.hpp"
+
+#include <QString>
+
+class QSvgRenderer;
+
+namespace chatterino {
+
+/// @brief A button displaying SVGs.
+///
+/// The source can be specified per theme (dark/light)
+/// and will get automatically updated when the theme changes.
+///
+/// To set the size, use #setInnerHeight(). The width is adjusted according
+/// to the aspect ratio of the SVG. If the button should scale with the UI,
+/// turn on auto-scaling (@see #setAutoScale()), which will scale the button
+/// and padding according to the current UI-scale (linearly).
+///
+/// The button has #padding() around the SVG.
+class SvgButton : public Button
+{
+    Q_OBJECT
+
+public:
+    /// Source configuration for the button
+    struct Src {
+        /// Source to load in a dark theme
+        QString dark;
+        /// Source to load in a light theme
+        QString light;
+    };
+
+    [[nodiscard]] SvgButton(Src source, BaseWidget *parent = nullptr,
+                            QSize padding = {6, 3});
+
+    /// Returns the current source configuration.
+    [[nodiscard]] Src source() const;
+
+    /// Setter for #source()
+    void setSource(Src source);
+
+    /// @brief Returns the padding inside the button.
+    ///
+    /// `width` is the padding applied horizontally (left and right).
+    /// `height` is the padding applied vertically (top and bottom).
+    ///
+    /// By default, the button has a vertical padding of 3 and a horizontal padding of 6.
+    [[nodiscard]] QSize padding() const;
+
+    /// Setter for #padding()
+    void setPadding(QSize padding);
+
+protected:
+    void themeChangedEvent() override;
+    void scaleChangedEvent(float scale) override;
+    void resizeEvent(QResizeEvent *e) override;
+
+    void paintContent(QPainter &painter) override;
+
+private:
+    [[nodiscard]] QString currentSvgPath() const;
+
+    Src source_;
+    QSvgRenderer *svg_;
+    QSize padding_;
+};
+
+}  // namespace chatterino