Add Qt3 development HEAD version

1 files changed, 565 insertions, 0 deletions

diff --git a/src/widgets/qrangecontrol.cpp b/src/widgets/qrangecontrol.cpp
new file mode 100644
index 0000000..c329831
--- /dev/null
+++ b/src/widgets/qrangecontrol.cpp
@@ -0,0 +1,565 @@
+/****************************************************************************
+**
+** Implementation of QRangeControl class
+**
+** Created : 940427
+**
+** Copyright (C) 1992-2008 Trolltech ASA.  All rights reserved.
+**
+** This file is part of the widgets module of the Qt GUI Toolkit.
+**
+** This file may be used under the terms of the GNU General
+** Public License versions 2.0 or 3.0 as published by the Free
+** Software Foundation and appearing in the files LICENSE.GPL2
+** and LICENSE.GPL3 included in the packaging of this file.
+** Alternatively you may (at your option) use any later version
+** of the GNU General Public License if such license has been
+** publicly approved by Trolltech ASA (or its successors, if any)
+** and the KDE Free Qt Foundation.
+**
+** Please review the following information to ensure GNU General
+** Public Licensing requirements will be met:
+** http://trolltech.com/products/qt/licenses/licensing/opensource/.
+** If you are unsure which license is appropriate for your use, please
+** review the following information:
+** http://trolltech.com/products/qt/licenses/licensing/licensingoverview
+** or contact the sales department at sales@trolltech.com.
+**
+** This file may be used under the terms of the Q Public License as
+** defined by Trolltech ASA and appearing in the file LICENSE.QPL
+** included in the packaging of this file.  Licensees holding valid Qt
+** Commercial licenses may use this file in accordance with the Qt
+** Commercial License Agreement provided with the Software.
+**
+** This file is provided "AS IS" with NO WARRANTY OF ANY KIND,
+** INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE. Trolltech reserves all rights not granted
+** herein.
+**
+**********************************************************************/
+
+#include "qrangecontrol.h"
+#ifndef QT_NO_RANGECONTROL
+#include "qglobal.h"
+#include <limits.h>
+
+static bool sumOutOfRange(int current, int add);
+
+
+/*!
+    \class QRangeControl qrangecontrol.h
+    \brief The QRangeControl class provides an integer value within a range.
+
+    \ingroup misc
+
+    Although originally designed for the QScrollBar widget, the
+    QRangeControl can also be used in conjunction with other widgets
+    such as QSlider and QSpinBox. Here are the five main concepts in
+    the class:
+
+    \list 1
+
+    \i \e{Current value} The bounded integer that
+    QRangeControl maintains. value() returns it, and several
+    functions, including setValue(), set it.
+
+    \i \e{Minimum} The lowest value that value() can ever
+    return. Returned by minValue() and set by setRange() or one of the
+    constructors.
+
+    \i \e{Maximum} The highest value that value() can ever
+    return. Returned by maxValue() and set by setRange() or one of the
+    constructors.
+
+    \i \e{Line step} The smaller of two natural steps that
+    QRangeControl provides and typically corresponds to the user
+    pressing an arrow key. The line step is returned by lineStep()
+    and set using setSteps(). The functions addLine() and
+    subtractLine() respectively increment and decrement the current
+    value by lineStep().
+
+    \i \e{Page step} The larger of two natural steps that
+    QRangeControl provides and typically corresponds to the user
+    pressing PageUp or PageDown. The page step is returned by
+    pageStep() and set using setSteps(). The functions addPage() and
+    substractPage() respectively increment and decrement the current
+    value by pageStep().
+
+    \endlist
+
+    Unity (1) may be viewed as a third step size. setValue() lets you
+    set the current value to any integer in the allowed range, not
+    just minValue() + \e n * lineStep() for integer values of \e n.
+    Some widgets may allow the user to set any value at all; others
+    may just provide multiples of lineStep() or pageStep().
+
+    QRangeControl provides three virtual functions that are well
+    suited for updating the on-screen representation of range controls
+    and emitting signals: valueChange(), rangeChange() and
+    stepChange().
+
+    QRangeControl also provides a function called bound() which lets
+    you force arbitrary integers to be within the allowed range of the
+    range control.
+
+    We recommend that all widgets that inherit QRangeControl provide
+    at least a signal called valueChanged(); many widgets will want to
+    provide addStep(), addPage(), substractStep() and substractPage()
+    as slots.
+
+    Note that you must use multiple inheritance if you plan to
+    implement a widget using QRangeControl because QRangeControl is
+    not derived from QWidget.
+*/
+
+
+/*!
+    Constructs a range control with a minimum value of 0, maximum
+    value of 99, line step of 1, page step of 10 and initial value 0.
+*/
+
+QRangeControl::QRangeControl()
+{
+    minVal  = 0;
+    maxVal  = 99;
+    line    = 1;
+    page    = 10;
+    val	    = 0;
+    prevVal = -1;
+    d	    = 0;
+}
+
+/*!
+    Constructs a range control whose value can never be smaller than
+    \a minValue or greater than \a maxValue, whose line step size is
+    \a lineStep and page step size is \a pageStep and whose value is
+    initially \a value (which is guaranteed to be in range using
+    bound()).
+*/
+
+QRangeControl::QRangeControl( int minValue, int maxValue,
+			      int lineStep, int pageStep,
+			      int value )
+{
+    minVal  = minValue;
+    maxVal  = maxValue;
+    line    = QABS( lineStep );
+    page    = QABS( pageStep );
+    prevVal = minVal - 1;
+    val	    = bound( value );
+    d	    = 0;
+}
+
+/*!
+    Destroys the range control
+*/
+
+QRangeControl::~QRangeControl()
+{
+}
+
+
+/*!
+    \fn int QRangeControl::value() const
+
+    Returns the current range control value. This is guaranteed to be
+    within the range [minValue(), maxValue()].
+
+    \sa setValue() prevValue()
+*/
+
+/*!
+    \fn int QRangeControl::prevValue() const
+
+    Returns the previous value of the range control. "Previous value"
+    means the value before the last change occurred. Setting a new
+    range may affect the value, too, because the value is forced to be
+    inside the specified range. When the range control is initially
+    created, this is the same as value().
+
+    prevValue() can be outside the current legal range if a call to
+    setRange() causes the current value to change. For example, if the
+    range was [0, 1000] and the current value is 500, setRange(0, 400)
+    makes value() return 400 and prevValue() return 500.
+
+    \sa value() setRange()
+*/
+
+/*!
+    Sets the range control's value to \a value and forces it to be
+    within the legal range.
+
+    Calls the virtual valueChange() function if the new value is
+    different from the previous value. The old value can still be
+    retrieved using prevValue().
+
+    \sa value()
+*/
+
+void QRangeControl::setValue( int value )
+{
+    directSetValue( value );
+    if ( prevVal != val )
+	valueChange();
+}
+
+/*!
+    Sets the range control \a value directly without calling
+    valueChange().
+
+    Forces the new \a value to be within the legal range.
+
+    You will rarely have to call this function. However, if you want
+    to change the range control's value inside the overloaded method
+    valueChange(), setValue() would call the function valueChange()
+    again. To avoid this recursion you must use directSetValue()
+    instead.
+
+    \sa setValue()
+*/
+
+void QRangeControl::directSetValue(int value)
+{
+    prevVal = val;
+    val = bound( value );
+}
+
+/*!
+    Equivalent to \c{setValue( value() + pageStep() )}.
+
+    If the value is changed, then valueChange() is called.
+
+    \sa subtractPage() addLine() setValue()
+*/
+
+void QRangeControl::addPage()
+{
+    if (!sumOutOfRange(value(), pageStep()))
+        setValue(value() + pageStep());
+}
+
+/*!
+    Equivalent to \c{setValue( value() - pageStep() )}.
+
+    If the value is changed, then valueChange() is called.
+
+    \sa addPage() subtractLine() setValue()
+*/
+
+void QRangeControl::subtractPage()
+{
+    if (!sumOutOfRange(value(), -pageStep()))
+        setValue(value() - pageStep());
+}
+
+/*!
+    Equivalent to \c{setValue( value() + lineStep() )}.
+
+    If the value is changed, then valueChange() is called.
+
+    \sa subtractLine() addPage() setValue()
+*/
+
+void QRangeControl::addLine()
+{
+    if (!sumOutOfRange(value(), lineStep()))
+        setValue(value() + lineStep());
+}
+
+/*!
+    Equivalent to \c{setValue( value() - lineStep() )}.
+
+    If the value is changed, then valueChange() is called.
+
+    \sa addLine() subtractPage() setValue()
+*/
+
+void QRangeControl::subtractLine()
+{
+    if (!sumOutOfRange(value(), -lineStep()))
+        setValue(value() - lineStep());
+}
+
+
+/*!
+    \fn int QRangeControl::minValue() const
+
+    Returns the minimum value of the range.
+
+    \sa setMinValue() setRange() maxValue()
+*/
+
+/*!
+    \fn int QRangeControl::maxValue() const
+
+    Returns the maximum value of the range.
+
+    \sa setMaxValue() setRange() minValue()
+*/
+
+/*!
+    Sets the minimum value of the range to \a minVal.
+
+    If necessary, the maxValue() is adjusted so that the range remains
+    valid.
+
+    \sa minValue() setMaxValue()
+*/
+void QRangeControl::setMinValue( int minVal )
+{
+    int maxVal = maxValue();
+    if ( maxVal < minVal )
+	maxVal = minVal;
+    setRange( minVal, maxVal );
+}
+
+/*!
+    Sets the minimum value of the range to \a maxVal.
+
+    If necessary, the minValue() is adjusted so that the range remains
+    valid.
+
+    \sa maxValue() setMinValue()
+*/
+void QRangeControl::setMaxValue( int maxVal )
+{
+    int minVal = minValue();
+    if ( minVal > maxVal )
+	minVal = maxVal;
+    setRange( minVal, maxVal );
+}
+
+/*!
+    Sets the range control's minimum value to \a minValue and its
+    maximum value to \a maxValue.
+
+    Calls the virtual rangeChange() function if one or both of the new
+    minimum and maximum values are different from the previous
+    setting. Calls the virtual valueChange() function if the current
+    value is adjusted because it was outside the new range.
+
+    If \a maxValue is smaller than \a minValue, \a minValue becomes
+    the only legal value.
+
+    \sa minValue() maxValue()
+*/
+
+void QRangeControl::setRange( int minValue, int maxValue )
+{
+    if ( minValue > maxValue ) {
+#if defined(QT_CHECK_RANGE)
+	qWarning( "QRangeControl::setRange: minValue %d > maxValue %d",
+		  minValue, maxValue );
+#endif
+	maxValue = minValue;
+    }
+    if ( minValue == minVal && maxValue == maxVal )
+	return;
+    minVal = minValue;
+    maxVal = maxValue;
+    int tmp = bound( val );
+    rangeChange();
+    if ( tmp != val ) {
+	prevVal = val;
+	val = tmp;
+	valueChange();
+    }
+}
+
+
+/*!
+    \fn int QRangeControl::lineStep() const
+
+    Returns the line step.
+
+    \sa setSteps() pageStep()
+*/
+
+/*!
+    \fn int QRangeControl::pageStep() const
+
+    Returns the page step.
+
+    \sa setSteps() lineStep()
+*/
+
+/*!
+    Sets the range's line step to \a lineStep and page step to \a
+    pageStep.
+
+    Calls the virtual stepChange() function if the new line step
+    or page step are different from the previous settings.
+
+    \sa lineStep() pageStep() setRange()
+*/
+
+void QRangeControl::setSteps( int lineStep, int pageStep )
+{
+    if ( lineStep != line || pageStep != page ) {
+	line = QABS( lineStep );
+	page = QABS( pageStep );
+	stepChange();
+    }
+}
+
+
+/*!
+    This virtual function is called whenever the range control value
+    changes. You can reimplement it if you want to be notified when
+    the value changes. The default implementation does nothing.
+
+    Note that this method is called after the value has changed. The
+    previous value can be retrieved using prevValue().
+
+    \sa setValue(), addPage(), subtractPage(), addLine(),
+    subtractLine() rangeChange(), stepChange()
+*/
+
+void QRangeControl::valueChange()
+{
+}
+
+
+/*!
+    This virtual function is called whenever the range control's range
+    changes. You can reimplement it if you want to be notified when
+    the range changes. The default implementation does nothing.
+
+    Note that this method is called after the range has changed.
+
+    \sa setRange(), valueChange(), stepChange()
+*/
+
+void QRangeControl::rangeChange()
+{
+}
+
+
+/*!
+    This virtual function is called whenever the range control's
+    line or page step settings change. You can reimplement it if you
+    want to be notified when the step changes. The default
+    implementation does nothing.
+
+    Note that this method is called after a step setting has changed.
+
+    \sa setSteps(), rangeChange(), valueChange()
+*/
+
+void QRangeControl::stepChange()
+{
+}
+
+
+/*!
+    Forces the value \a v to be within the range from minValue() to
+    maxValue() inclusive, and returns the result.
+
+    This function is provided so that you can easily force other
+    numbers than value() into the allowed range. You do not need to
+    call it in order to use QRangeControl itself.
+
+    \sa setValue() value() minValue() maxValue()
+*/
+
+int QRangeControl::bound( int v ) const
+{
+    if ( v < minVal )
+	return minVal;
+    if ( v > maxVal )
+	return maxVal;
+    return v;
+}
+
+
+/*!
+    Converts \a logical_val to a pixel position. minValue() maps to 0,
+    maxValue() maps to \a span and other values are distributed evenly
+    in-between.
+
+    This function can handle the entire integer range without
+    overflow, providing \a span is \<= 4096.
+
+    Calling this method is useful when actually drawing a range
+    control such as a QScrollBar on-screen.
+
+    \sa valueFromPosition()
+*/
+
+int QRangeControl::positionFromValue( int logical_val, int span ) const
+{
+    if ( span <= 0 || logical_val < minValue() || maxValue() <= minValue() )
+	return 0;
+    if ( logical_val > maxValue() )
+	return span;
+
+    uint range = maxValue() - minValue();
+    uint p = logical_val - minValue();
+
+    if ( range > (uint)INT_MAX/4096 ) {
+	const int scale = 4096*2;
+	return ( (p/scale) * span ) / (range/scale);
+	// ### the above line is probably not 100% correct
+	// ### but fixing it isn't worth the extreme pain...
+    } else if ( range > (uint)span ) {
+	return (2*p*span + range) / (2*range);
+    } else {
+	uint div = span / range;
+	uint mod = span % range;
+	return p*div + (2*p*mod + range) / (2*range);
+    }
+    //equiv. to (p*span)/range + 0.5
+    // no overflow because of this implicit assumption:
+    // span <= 4096
+}
+
+
+/*!
+    Converts the pixel position \a pos to a value. 0 maps to
+    minValue(), \a span maps to maxValue() and other values are
+    distributed evenly in-between.
+
+    This function can handle the entire integer range without
+    overflow.
+
+    Calling this method is useful if you actually implemented a range
+    control widget such as QScrollBar and want to handle mouse press
+    events. This function then maps screen coordinates to the logical
+    values.
+
+    \sa positionFromValue()
+*/
+
+int QRangeControl::valueFromPosition( int pos, int span ) const
+{
+    if ( span <= 0 || pos <= 0 )
+	return minValue();
+    if ( pos >= span )
+	return maxValue();
+
+    uint range = maxValue() - minValue();
+
+    if ( (uint)span > range )
+	return  minValue() + (2*pos*range + span) / (2*span);
+    else {
+	uint div = range / span;
+	uint mod = range % span;
+	return  minValue() + pos*div + (2*pos*mod + span) / (2*span);
+    }
+    // equiv. to minValue() + (pos*range)/span + 0.5
+    // no overflow because of this implicit assumption:
+    // pos <= span < sqrt(INT_MAX+0.0625)+0.25 ~ sqrt(INT_MAX)
+}
+
+static bool sumOutOfRange(int current, int add)
+{
+    if (add > 0 && INT_MAX - add < current) {
+        return true;
+    }
+    if (add < 0 && INT_MIN - add > current) {
+        return true;
+    }
+    return false;
+}
+
+#endif