From 720a6d856e8d2d132e7482afe30fb81535727a2e Mon Sep 17 00:00:00 2001
From: Andreas Heinisch <andreas.heinisch@yahoo.de>
Date: Wed, 7 Oct 2026 13:36:47 +0200
Subject: [PATCH] tdf#171730 - Keep slider markers in sync in the Pick a Color
 dialog

The markers of the vertical color slider were only updated when the hex
field was changed. Switching the color component via the radio buttons
left the markers at their current position.

In addition, markers did not match the start color when the dialog was
opened.

The level will now be calculated on every color update and once the
slider is shown.

Change-Id: Ie31a6e93e2a6bbf10f0cdf3307b81b735662a3c0
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/211962
Tested-by: Jenkins
Reviewed-by: Andreas Heinisch <andreas.heinisch@yahoo.de>
---
 vcl/inc/colorpicker.hxx           |  9 +++++++--
 vcl/source/window/colorpicker.cxx | 20 +++++++++++++-------
 2 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/vcl/inc/colorpicker.hxx b/vcl/inc/colorpicker.hxx
index 8f9cdb40cfdb..a7a7b0b53d69 100644
--- a/vcl/inc/colorpicker.hxx
+++ b/vcl/inc/colorpicker.hxx
@@ -152,15 +152,19 @@ public:
     double GetValue() const { return mdValue; }
 
     void SetModifyHdl(const Link<ColorSliderControl&, void>& rLink) { maModifyHdl = rLink; }
+    void SetResizeHdl(const Link<ColorSliderControl&, void>& rLink) { maResizeHdl = rLink; }
 
-    sal_Int16 GetLevel() const { return mnLevel; }
+    sal_Int16 GetLevel() const
+    {
+        return static_cast<sal_Int16>((1.0 - mdValue) * GetOutputSizePixel().Height());
+    }
 
 private:
     Link<ColorSliderControl&, void> maModifyHdl;
+    Link<ColorSliderControl&, void> maResizeHdl;
     Color maColor;
     ColorMode meMode;
     VclPtr<VirtualDevice> mxBitmap;
-    sal_Int16 mnLevel;
     double mdValue;
 };
 
@@ -221,6 +225,7 @@ private:
 
     DECL_LINK(ColorFieldControlModifydl, ColorFieldControl&, void);
     DECL_LINK(ColorSliderControlModifyHdl, ColorSliderControl&, void);
+    DECL_LINK(ColorSliderResizeHdl, ColorSliderControl&, void);
     DECL_LINK(ColorModifyMetricHdl, weld::MetricSpinButton&, void);
     DECL_LINK(ColorModifySpinHdl, weld::SpinButton&, void);
     DECL_LINK(ColorModifyEditHdl, weld::Entry&, void);
diff --git a/vcl/source/window/colorpicker.cxx b/vcl/source/window/colorpicker.cxx
index 3cb023ad576e..f31ca8c578b4 100644
--- a/vcl/source/window/colorpicker.cxx
+++ b/vcl/source/window/colorpicker.cxx
@@ -417,7 +417,6 @@ void ColorFieldControl::UpdatePosition()
 
 ColorSliderControl::ColorSliderControl()
     : meMode( DefaultMode )
-    , mnLevel( 0 )
     , mdValue( -1.0 )
 {
 }
@@ -519,7 +518,6 @@ void ColorSliderControl::ChangePosition(tools::Long nY)
     else if (nY > nHeight)
         nY = nHeight;
 
-    mnLevel = nY;
     mdValue = double(nHeight - nY) / double(nHeight);
 }
 
@@ -567,6 +565,7 @@ void ColorSliderControl::Resize()
 {
     CustomWidgetController::Resize();
     UpdateBitmap();
+    maResizeHdl.Call(*this);
 }
 
 void ColorSliderControl::Modify()
@@ -581,7 +580,6 @@ void ColorSliderControl::SetValue(const Color& rColor, ColorMode eMode, double d
     {
         maColor = rColor;
         mdValue = dValue;
-        mnLevel = static_cast<sal_Int16>((1.0-dValue) * GetOutputSizePixel().Height());
         meMode = eMode;
         if (bUpdateBitmap)
             UpdateBitmap();
@@ -618,6 +616,7 @@ ColorPickerDialog::ColorPickerDialog(weld::Window* pParent, const Color& rColor,
 {
     m_aColorField.SetModifyHdl( LINK( this, ColorPickerDialog, ColorFieldControlModifydl ) );
     m_aColorSlider.SetModifyHdl( LINK( this, ColorPickerDialog, ColorSliderControlModifyHdl ) );
+    m_aColorSlider.SetResizeHdl(LINK(this, ColorPickerDialog, ColorSliderResizeHdl));
 
     int nMargin = (m_xFISliderLeft->get_preferred_size().Height() + 1) / 2;
     m_xColorSlider->set_margin_top(nMargin);
@@ -769,12 +768,12 @@ void ColorPickerDialog::update_color( UpdateFlags n )
         }
     }
 
+    // tdf#171730 - always sync slider markers with current slider level
+    m_xFISliderLeft->set_margin_top(m_aColorSlider.GetLevel());
+    m_xFISliderRight->set_margin_top(m_aColorSlider.GetLevel());
+
     if (n & UpdateFlags::Hex) // update hex
-    {
-        m_xFISliderLeft->set_margin_top(m_aColorSlider.GetLevel());
-        m_xFISliderRight->set_margin_top(m_aColorSlider.GetLevel());
         m_xEDHex->SetColor(aColor);
-    }
     m_aColorPreview.SetColor(aColor);
 }
 
@@ -842,6 +841,13 @@ IMPL_LINK_NOARG(ColorPickerDialog, ColorSliderControlModifyHdl, ColorSliderContr
     update_color(UpdateFlags::All & ~UpdateFlags::ColorSlider);
 }
 
+IMPL_LINK_NOARG(ColorPickerDialog, ColorSliderResizeHdl, ColorSliderControl&, void)
+{
+    // tdf#171730 - sync slider markers with current slider level
+    m_xFISliderLeft->set_margin_top(m_aColorSlider.GetLevel());
+    m_xFISliderRight->set_margin_top(m_aColorSlider.GetLevel());
+}
+
 IMPL_LINK(ColorPickerDialog, ColorModifyMetricHdl, weld::MetricSpinButton&, rEdit, void)
 {
     UpdateFlags n = UpdateFlags::NONE;