Merge branch 'spinctrl-digits'

Improve setting the number of digits in wxSpinCtrlDouble and make it
consistent on all platforms.

See https://github.com/wxWidgets/wxWidgets/pull/2348

Closes #17085.

include/wx/generic/spinctlg.h

@@ -382,13 +382,7 @@ public:
                 long style = wxSP_ARROW_KEYS,
                 double min = 0, double max = 100, double initial = 0,
                 double inc = 1,
-                const wxString& name = wxT("wxSpinCtrlDouble"))
+                const wxString& name = wxT("wxSpinCtrlDouble"));
-    {
-        DetermineDigits(inc);
-        return wxSpinCtrlGenericBase::Create(parent, id, value, pos, size,
-                                             style, min, max, initial,
-                                             inc, name);
-    }
 
     // accessors
     double GetValue(wxSPINCTRL_GETVALUE_FIX) const { return DoGetValue(); }
@@ -402,7 +396,7 @@ public:
         { wxSpinCtrlGenericBase::SetValue(value); }
     void SetValue(double value)                 { DoSetValue(value, SendEvent_None); }
     void SetRange(double minVal, double maxVal) { DoSetRange(minVal, maxVal); }
-    void SetIncrement(double inc)               { DoSetIncrement(inc); }
+    void SetIncrement(double inc);
     void SetDigits(unsigned digits);
 
     // We don't implement bases support for floating point numbers, this is not
@@ -416,7 +410,6 @@ protected:
     virtual bool DoTextToValue(const wxString& text, double *val) wxOVERRIDE;
     virtual wxString DoValueToText(double val) wxOVERRIDE;
     virtual void ResetTextValidator() wxOVERRIDE;
-    void DetermineDigits(double inc);
 
     unsigned m_digits;
 
@@ -424,10 +417,16 @@ private:
     // Common part of all ctors.
     void Init()
     {
-        m_digits = 0;
+        DoSetDigits(0);
-        m_format = wxASCII_STR("%0.0f");
     }
 
+    // Just set the number of digits and the format unconditionally.
+    void DoSetDigits(unsigned digits);
+
+    // Call DoSetDigits() and update the appearance.
+    void DoSetDigitsAndUpdate(unsigned digits);
+
+
     wxString m_format;
 
     wxDECLARE_DYNAMIC_CLASS(wxSpinCtrlDouble);

include/wx/gtk/spinctrl.h

@@ -243,7 +243,7 @@ public:
     void SetValue(const wxString& value) wxOVERRIDE        { wxSpinCtrlGTKBase::SetValue(value); } // visibility problem w/ gcc
     void SetValue(double value)                 { DoSetValue(value); }
     void SetRange(double minVal, double maxVal) { DoSetRange(minVal, maxVal); }
-    void SetIncrement(double inc)               { DoSetIncrement(inc); }
+    void SetIncrement(double inc);
     void SetDigits(unsigned digits);
 
     virtual int GetBase() const wxOVERRIDE { return 10; }

include/wx/private/spinctrl.h

@@ -28,6 +28,14 @@ extern wxSize GetBestSize(const wxControl* spin, int minVal, int maxVal, int bas
 
 // Helper function to check if given combination of range and base is valid.
 extern bool IsBaseCompatibleWithRange(int minVal, int maxVal, int base);
+
+// Maximum number of digits returned by DetermineDigits().
+const unsigned SPINCTRLDBL_MAX_DIGITS = 20;
+
+// Return the number of digits required to show the numbers using the
+// specified increment without loss of precision.
+extern unsigned DetermineDigits(double inc);
+
 } // namespace wxSpinCtrlImpl
 
 #endif // _WX_PRIVATE_SPINCTRL_H_

interface/wx/spinctrl.h

@@ -354,8 +354,15 @@ public:
 
     /**
         Sets the increment value.
-        @note You may also need to change the precision of the value
+
-        using SetDigits().
+        Using this method changes the number of digits used by the control to
+        at least match the value of @a inc, e.g. using the increment of @c 0.01
+        sets the number of digits to 2 if it had been less than 2 before.
+        However it doesn't change the number of digits if it had been already
+        high enough.
+
+        In any case, you may call SetDigits() explicitly to override the
+        automatic determination of the number of digits.
     */
     void SetIncrement(double inc);
 

src/common/spinctrlcmn.cpp

@@ -26,6 +26,8 @@
 
 #include "wx/private/spinctrl.h"
 
+#include <math.h>
+
 wxDEFINE_EVENT(wxEVT_SPINCTRL, wxSpinEvent);
 wxDEFINE_EVENT(wxEVT_SPINCTRLDOUBLE, wxSpinDoubleEvent);
 
@@ -140,4 +142,19 @@ bool wxSpinCtrlImpl::IsBaseCompatibleWithRange(int minVal, int maxVal, int base)
     return base == 10 || (minVal >= 0 && maxVal >= 0);
 }
 
+unsigned wxSpinCtrlImpl::DetermineDigits(double inc)
+{
+    // TODO-C++11: Use std::modf() to get the fractional part.
+    inc = fabs(inc);
+    inc -= static_cast<int>(inc);
+    if ( inc > 0.0 )
+    {
+        return wxMin(SPINCTRLDBL_MAX_DIGITS, -static_cast<int>(floor(log10(inc))));
+    }
+    else
+    {
+        return 0;
+    }
+}
+
 #endif // wxUSE_SPINCTRL

src/generic/spinctlg.cpp

@@ -723,10 +723,26 @@ void wxSpinCtrl::ResetTextValidator()
 // wxSpinCtrlDouble
 //-----------------------------------------------------------------------------
 
-#define SPINCTRLDBL_MAX_DIGITS 20
-
 wxIMPLEMENT_DYNAMIC_CLASS(wxSpinCtrlDouble, wxSpinCtrlGenericBase);
 
+bool
+wxSpinCtrlDouble::Create(wxWindow *parent,
+                         wxWindowID id,
+                         const wxString& value,
+                         const wxPoint& pos,
+                         const wxSize& size,
+                         long style,
+                         double min, double max, double initial,
+                         double inc,
+                         const wxString& name)
+{
+    DoSetDigits(wxSpinCtrlImpl::DetermineDigits(inc));
+
+    return wxSpinCtrlGenericBase::Create(parent, id, value, pos, size,
+                                         style, min, max, initial,
+                                         inc, name);
+}
+
 void wxSpinCtrlDouble::DoSendEvent()
 {
     wxSpinDoubleEvent event( wxEVT_SPINCTRLDOUBLE, GetId());
@@ -746,16 +762,36 @@ wxString wxSpinCtrlDouble::DoValueToText(double val)
     return wxString::Format(m_format, val);
 }
 
+void wxSpinCtrlDouble::SetIncrement(double inc)
+{
+    if ( inc == m_increment )
+        return;
+
+    DoSetIncrement(inc);
+
+    const unsigned digits = wxSpinCtrlImpl::DetermineDigits(inc);
+
+    // We don't decrease the number of digits here, as this is unnecessary and
+    // could be undesirable, but we do increase it if the current number is not
+    // high enough to show the numbers without losing precision.
+    if ( digits > m_digits )
+        DoSetDigitsAndUpdate(digits);
+}
+
 void wxSpinCtrlDouble::SetDigits(unsigned digits)
 {
-    wxCHECK_RET( digits <= SPINCTRLDBL_MAX_DIGITS, "too many digits for wxSpinCtrlDouble" );
+    wxCHECK_RET( digits <= wxSpinCtrlImpl::SPINCTRLDBL_MAX_DIGITS,
+                 "too many digits for wxSpinCtrlDouble" );
 
     if ( digits == m_digits )
         return;
 
-    m_digits = digits;
+    DoSetDigitsAndUpdate(digits);
+}
 
-    m_format.Printf(wxT("%%0.%ulf"), digits);
+void wxSpinCtrlDouble::DoSetDigitsAndUpdate(unsigned digits)
+{
+    DoSetDigits(digits);
 
     ResetTextValidator();
     m_textCtrl->InvalidateBestSize();
@@ -763,6 +799,13 @@ void wxSpinCtrlDouble::SetDigits(unsigned digits)
     DoSetValue(m_value, SendEvent_None);
 }
 
+void wxSpinCtrlDouble::DoSetDigits(unsigned digits)
+{
+    m_digits = digits;
+
+    m_format.Printf(wxT("%%0.%ulf"), digits);
+}
+
 void wxSpinCtrlDouble::ResetTextValidator()
 {
 #if wxUSE_VALIDATORS
@@ -772,16 +815,6 @@ void wxSpinCtrlDouble::ResetTextValidator()
 #endif // wxUSE_VALIDATORS
 }
 
-void wxSpinCtrlDouble::DetermineDigits(double inc)
-{
-    inc = fabs(inc);
-    if ( inc > 0.0 && inc < 1.0 )
-    {
-        m_digits = wxMin(SPINCTRLDBL_MAX_DIGITS, -static_cast<int>(floor(log10(inc))));
-        m_format.Printf("%%0.%ulf", m_digits);
-    }
-}
-
 #endif // wxUSE_SPINBTN
 
 #endif // !wxPort-with-native-spinctrl

src/gtk/spinctrl.cpp

@@ -643,6 +643,18 @@ void wxSpinCtrlDouble::GtkSetEntryWidth()
     gtk_entry_set_width_chars(GTK_ENTRY(m_widget), wxMax(lenMin, lenMax));
 }
 
+void wxSpinCtrlDouble::SetIncrement(double inc)
+{
+    DoSetIncrement(inc);
+
+    const unsigned digits = wxSpinCtrlImpl::DetermineDigits(inc);
+
+    // Increase the number of digits, if necessary, to show all numbers that
+    // can be obtained by using the new increment without loss of precision.
+    if ( digits > GetDigits() )
+        SetDigits(digits);
+}
+
 unsigned wxSpinCtrlDouble::GetDigits() const
 {
     wxCHECK_MSG( m_widget, 0, "invalid spin button" );

tests/controls/spinctrldbltest.cpp

@@ -217,18 +217,47 @@ TEST_CASE_METHOD(SpinCtrlDoubleTestCase,
 TEST_CASE_METHOD(SpinCtrlDoubleTestCase,
                  "SpinCtrlDouble::Digits", "[spinctrl][spinctrldouble]")
 {
-    m_spin->SetDigits(5);
+    // Setting increment should adjust the number of digits shown to be big
+    // enough to show numbers with the corresponding granularity.
+    m_spin->SetIncrement(0.1);
+    m_spin->SetValue(1.23456789);
+    CHECK( m_spin->GetTextValue() == "1.2" );
 
+    m_spin->SetIncrement(0.01);
+    m_spin->SetValue(1.23456789);
+    CHECK( m_spin->GetTextValue() == "1.23" );
+
+    m_spin->SetDigits(5);
     CHECK( m_spin->GetDigits() == 5 );
+    m_spin->SetValue(1.23456789);
+    CHECK( m_spin->GetTextValue() == "1.23457" );
+
+    // The number of digits shouldn't (implicitly) decrease however.
+    m_spin->SetIncrement(0.001);
+    m_spin->SetValue(1.23456789);
+    CHECK( m_spin->GetTextValue() == "1.23457" );
+
+    // Check that using increment greater than 1 also works.
+    m_spin->SetDigits(0);
+    m_spin->SetIncrement(2.5);
+    m_spin->SetValue(7.5);
+    CHECK( m_spin->GetTextValue() == "7.5" );
 }
 
 static inline unsigned int GetInitialDigits(double inc)
 {
-    wxSpinCtrlDouble* sc = new wxSpinCtrlDouble(wxTheApp->GetTopWindow(), wxID_ANY, wxEmptyString, wxDefaultPosition, wxDefaultSize, wxSP_ARROW_KEYS,
+    wxScopedPtr<wxSpinCtrlDouble> sc(new wxSpinCtrlDouble
-        0, 50, 0, inc);
+        (
-    unsigned int digits = sc->GetDigits();
+            wxTheApp->GetTopWindow(),
-    delete sc;
+            wxID_ANY,
-    return digits;
+            wxEmptyString,
+            wxDefaultPosition,
+            wxDefaultSize,
+            wxSP_ARROW_KEYS,
+            0, 50, 0,
+            inc
+        ));
+    return sc->GetDigits();
 }
 
 TEST_CASE("SpinCtrlDouble::InitialDigits", "[spinctrldouble][initialdigits]")