LibGUI: Add movement methods to AbstractSlider

These methods give us a simple way to move up and down the slider,
without needing to repeat the 'set_value(value() + some_value)'
pattern that multiple applications and libraries use.

1 files changed, 7 insertions, 0 deletions

diff --git a/Userland/Libraries/LibGUI/AbstractSlider.h b/Userland/Libraries/LibGUI/AbstractSlider.h
index a254eb4808..7d22aa7cc3 100644
--- a/Userland/Libraries/LibGUI/AbstractSlider.h
+++ b/Userland/Libraries/LibGUI/AbstractSlider.h
@@ -38,6 +38,13 @@ public:
     void set_page_step(int page_step);
     void set_jump_to_cursor(bool b) { m_jump_to_cursor = b; }
 
+    void increase_slider_by(int delta) { set_value(value() + delta); }
+    void decrease_slider_by(int delta) { set_value(value() - delta); }
+    void increase_slider_by_page_steps(int page_steps) { set_value(value() + page_step() * page_steps); }
+    void decrease_slider_by_page_steps(int page_steps) { set_value(value() - page_step() * page_steps); }
+    void increase_slider_by_steps(int steps) { set_value(value() + step() * steps); }
+    void decrease_slider_by_steps(int steps) { set_value(value() - step() * steps); }
+
     Function<void(int)> on_change;
 
 protected: