//------------------------------------------------------------------------------
// emScalarField.h
//
// Copyright (C) 2005-2010,2014,2016 Oliver Hamann.
//
// Homepage: http://eaglemode.sourceforge.net/
//
// This program is free software: you can redistribute it and/or modify it under
// the terms of the GNU General Public License version 3 as published by the
// Free Software Foundation.
//
// This program is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
// FOR A PARTICULAR PURPOSE. See the GNU General Public License version 3 for
// more details.
//
// You should have received a copy of the GNU General Public License version 3
// along with this program. If not, see <http://www.gnu.org/licenses/>.
//------------------------------------------------------------------------------

#ifndef emScalarField_h
#define emScalarField_h

#ifndef emBorder_h
#include <emCore/emBorder.h>
#endif


//==============================================================================
//=============================== emScalarField ================================
//==============================================================================

class emScalarField : public emBorder {

public:

        // Class for a data field panel showing a scalar value which can
        // optionally be edited by the user. The scalar value is a 64-bit signed
        // integer number, but on the shown scale the values can be translated
        // to any texts (e.g. rational numbers, names ,...).

        emScalarField(
                ParentArg parent, const emString & name,
                const emString & caption=emString(),
                const emString & description=emString(),
                const emImage & icon=emImage(),
                emInt64 minValue=0, emInt64 maxValue=10, emInt64 value=0,
                bool editable=false
        );
                // Constructor.
                // Arguments:
                //   parent      - Parent for this panel (emPanel or emView).
                //   name        - The name for this panel.
                //   caption     - The label's caption, or empty.
                //   description - The label's description, or empty.
                //   icon        - The label's icon, or empty.
                //   minValue    - Minimum allowed value.
                //   maxValue    - Maximum allowed value.
                //   value       - Initial value.
                //   editable    - Whether the value can be edited by the user.

        virtual ~emScalarField();
                // Destructor.

        bool IsEditable() const;
        void SetEditable(bool editable=true);
                // Whether the value can be edited by the user.

        emInt64 GetMinValue() const;
        emInt64 GetMaxValue() const;
        void SetMinValue(emInt64 minValue);
        void SetMaxValue(emInt64 maxValue);
        void SetMinMaxValues(emInt64 minValue, emInt64 maxValue);
                // Get/set the range of possible values.

        const emSignal & GetValueSignal() const;
                // This signal is signaled after each change of the value.

        emInt64 GetValue() const;
        void SetValue(emInt64 value);
                // Get/set the value.

        const emArray<emUInt64> & GetScaleMarkIntervals() const;
        void SetScaleMarkIntervals(const emArray<emUInt64> & intervals);
        void SetScaleMarkIntervals(unsigned interval1, unsigned interval2, ...);
                // Get/set the layout of scale marks. It is an array of
                // intervals between the scale marks of different size levels.
                // The first interval is for the largest scale marks, the second
                // is for the second-largest scale marks and so on. Thus, the
                // array must be sorted from large to small. For example, a
                // classic centimeter rule would have {10,5,1}, with the values
                // in millimeters. The default is {1}. The arguments to the
                // ellipse version method must be terminated by a 0. Note that
                // the ellipse version can take only 32-bit intervals (I am not
                // sure whether an ellipse on emUInt64 would be portable).

        bool IsNeverHidingMarks() const;
        void SetNeverHideMarks(bool neverHide);
                // By default, marks with an interval greater than
                // (MaxValue - MinValue) are automatically not shown, so that
                // the other marks can be seen better. Setting true here
                // disables that automatism.

        virtual void TextOfValue(char * buf, int bufSize, emInt64 value,
                                 emUInt64 markInterval) const;
                // Convert a scale mark value to a null-terminated character
                // string for display on the scale. The default implementation
                // uses the callback function set with SetTextOfValueFunc.

        void SetTextOfValueFunc(
                void(*textOfValueFunc)(
                        char * buf, int bufSize, emInt64 value,
                        emUInt64 markInterval, void * context
                ),
                void * context=NULL
        );
                // Set a function for converting a scale mark value to a
                // null-terminated character string for display on the scale.
                // The context argument is forwarded to the function for any
                // use. The default performs simple decimal conversion.

        static void DefaultTextOfValue(
                char * buf, int bufSize, emInt64 value, emUInt64 markInterval,
                void * context
        );
                // This is the default text-of-value-function. It performs
                // decimal conversion.

        double GetTextBoxTallness() const;
        void SetTextBoxTallness(double textBoxTallness);
                // Tallness of the text box of a scale mark. The default is 0.5.

        emUInt64 GetKeyboardInterval() const;
        void SetKeyboardInterval(emUInt64 kbInterval);
                // How much to add and sub to the value by '+' and '-' keys. The
                // default is zero which means to choose a good interval
                // automatically.

protected:

        virtual void ValueChanged();
                // Called when the value has changed.

        virtual void Input(emInputEvent & event, const emInputState & state,
                           double mx, double my);

        virtual bool HasHowTo() const;
        virtual emString GetHowTo() const;

        virtual void PaintContent(
                const emPainter & painter, double x, double y, double w,
                double h, emColor canvasColor
        ) const;

        virtual bool CheckMouse(double mx, double my, emInt64 * pValue) const;

private:

        enum DoScalarFieldFunc {
                SCALAR_FIELD_FUNC_PAINT,
                SCALAR_FIELD_FUNC_CHECK_MOUSE
        };
        void DoScalarField(
                DoScalarFieldFunc func, const emPainter * painter,
                emColor canvasColor,
                double mx, double my, emInt64 * pValue, bool * pHit
        ) const;

        void StepByKeyboard(int dir);

        bool Editable;
        emSignal ValueSignal;
        emInt64 MinValue,MaxValue;
        emInt64 Value;
        emArray<emUInt64> ScaleMarkIntervals;
        bool MarksNeverHidden;
        void(*TextOfValueFunc)(
                char * buf, int bufSize, emInt64 value, emUInt64 markInterval,
                void * context
        );
        void * TextOfValueFuncContext;
        double TextBoxTallness;
        emUInt64 KBInterval;
        bool Pressed;

        static const char * HowToScalarField;
        static const char * HowToReadOnly;
};

inline bool emScalarField::IsEditable() const
{
        return Editable;
}

inline emInt64 emScalarField::GetMinValue() const
{
        return MinValue;
}

inline emInt64 emScalarField::GetMaxValue() const
{
        return MaxValue;
}

inline const emSignal & emScalarField::GetValueSignal() const
{
        return ValueSignal;
}

inline emInt64 emScalarField::GetValue() const
{
        return Value;
}

inline const emArray<emUInt64> & emScalarField::GetScaleMarkIntervals() const
{
        return ScaleMarkIntervals;
}

inline bool emScalarField::IsNeverHidingMarks() const
{
        return MarksNeverHidden;
}

inline double emScalarField::GetTextBoxTallness() const
{
        return TextBoxTallness;
}

inline emUInt64 emScalarField::GetKeyboardInterval() const
{
        return KBInterval;
}


#endif