--- /dev/null
+/*
+ * Jexer - Java Text User Interface
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (C) 2019 Kevin Lamonte
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * @author Kevin Lamonte [kevin.lamonte@gmail.com]
+ * @version 1
+ */
+package jexer;
+
+/**
+ * Scrollable provides a public API for horizontal and vertical scrollbars.
+ * Note that not all Scrollables support both horizontal and vertical
+ * scrolling; for those that only support a subset, it is expected that the
+ * methods corresponding to the missing scrollbar quietly succeed without
+ * throwing any exceptions.
+ */
+public interface Scrollable {
+
+ /**
+ * Get the horizontal scrollbar, or null if this Viewport does not
+ * support horizontal scrolling.
+ *
+ * @return the horizontal scrollbar
+ */
+ public THScroller getHorizontalScroller();
+
+ /**
+ * Get the vertical scrollbar, or null if this Viewport does not support
+ * vertical scrolling.
+ *
+ * @return the vertical scrollbar
+ */
+ public TVScroller getVerticalScroller();
+
+ /**
+ * Get the value that corresponds to being on the top edge of the
+ * vertical scroll bar.
+ *
+ * @return the scroll value
+ */
+ public int getTopValue();
+
+ /**
+ * Set the value that corresponds to being on the top edge of the
+ * vertical scroll bar.
+ *
+ * @param topValue the new scroll value
+ */
+ public void setTopValue(final int topValue);
+
+ /**
+ * Get the value that corresponds to being on the bottom edge of the
+ * vertical scroll bar.
+ *
+ * @return the scroll value
+ */
+ public int getBottomValue();
+
+ /**
+ * Set the value that corresponds to being on the bottom edge of the
+ * vertical scroll bar.
+ *
+ * @param bottomValue the new scroll value
+ */
+ public void setBottomValue(final int bottomValue);
+
+ /**
+ * Get current value of the vertical scroll.
+ *
+ * @return the scroll value
+ */
+ public int getVerticalValue();
+
+ /**
+ * Set current value of the vertical scroll.
+ *
+ * @param value the new scroll value
+ */
+ public void setVerticalValue(final int value);
+
+ /**
+ * Get the increment for clicking on an arrow on the vertical scrollbar.
+ *
+ * @return the increment value
+ */
+ public int getVerticalSmallChange();
+
+ /**
+ * Set the increment for clicking on an arrow on the vertical scrollbar.
+ *
+ * @param smallChange the new increment value
+ */
+ public void setVerticalSmallChange(final int smallChange);
+
+ /**
+ * Get the increment for clicking in the bar between the box and an
+ * arrow on the vertical scrollbar.
+ *
+ * @return the increment value
+ */
+ public int getVerticalBigChange();
+
+ /**
+ * Set the increment for clicking in the bar between the box and an
+ * arrow on the vertical scrollbar.
+ *
+ * @param bigChange the new increment value
+ */
+ public void setVerticalBigChange(final int bigChange);
+
+ /**
+ * Perform a small step change up.
+ */
+ public void verticalDecrement();
+
+ /**
+ * Perform a small step change down.
+ */
+ public void verticalIncrement();
+
+ /**
+ * Perform a big step change up.
+ */
+ public void bigVerticalDecrement();
+
+ /**
+ * Perform a big step change down.
+ */
+ public void bigVerticalIncrement();
+
+ /**
+ * Go to the top edge of the vertical scroller.
+ */
+ public void toTop();
+
+ /**
+ * Go to the bottom edge of the vertical scroller.
+ */
+ public void toBottom();
+
+ /**
+ * Get the value that corresponds to being on the left edge of the
+ * horizontal scroll bar.
+ *
+ * @return the scroll value
+ */
+ public int getLeftValue();
+
+ /**
+ * Set the value that corresponds to being on the left edge of the
+ * horizontal scroll bar.
+ *
+ * @param leftValue the new scroll value
+ */
+ public void setLeftValue(final int leftValue);
+
+ /**
+ * Get the value that corresponds to being on the right edge of the
+ * horizontal scroll bar.
+ *
+ * @return the scroll value
+ */
+ public int getRightValue();
+
+ /**
+ * Set the value that corresponds to being on the right edge of the
+ * horizontal scroll bar.
+ *
+ * @param rightValue the new scroll value
+ */
+ public void setRightValue(final int rightValue);
+
+ /**
+ * Get current value of the horizontal scroll.
+ *
+ * @return the scroll value
+ */
+ public int getHorizontalValue();
+
+ /**
+ * Set current value of the horizontal scroll.
+ *
+ * @param value the new scroll value
+ */
+ public void setHorizontalValue(final int value);
+
+ /**
+ * Get the increment for clicking on an arrow on the horizontal
+ * scrollbar.
+ *
+ * @return the increment value
+ */
+ public int getHorizontalSmallChange();
+
+ /**
+ * Set the increment for clicking on an arrow on the horizontal
+ * scrollbar.
+ *
+ * @param smallChange the new increment value
+ */
+ public void setHorizontalSmallChange(final int smallChange);
+
+ /**
+ * Get the increment for clicking in the bar between the box and an
+ * arrow on the horizontal scrollbar.
+ *
+ * @return the increment value
+ */
+ public int getHorizontalBigChange();
+
+ /**
+ * Set the increment for clicking in the bar between the box and an
+ * arrow on the horizontal scrollbar.
+ *
+ * @param bigChange the new increment value
+ */
+ public void setHorizontalBigChange(final int bigChange);
+
+ /**
+ * Perform a small step change left.
+ */
+ public void horizontalDecrement();
+
+ /**
+ * Perform a small step change right.
+ */
+ public void horizontalIncrement();
+
+ /**
+ * Perform a big step change left.
+ */
+ public void bigHorizontalDecrement();
+
+ /**
+ * Perform a big step change right.
+ */
+ public void bigHorizontalIncrement();
+
+ /**
+ * Go to the left edge of the horizontal scroller.
+ */
+ public void toLeft();
+
+ /**
+ * Go to the right edge of the horizontal scroller.
+ */
+ public void toRight();
+
+ /**
+ * Go to the top-left edge of the horizontal and vertical scrollers.
+ */
+ public void toHome();
+
+ /**
+ * Go to the bottom-right edge of the horizontal and vertical scrollers.
+ */
+ public void toEnd();
+
+}