*/
package jexer;
+import jexer.bits.CellAttributes;
+import jexer.bits.GraphicsChars;
+import jexer.event.TMouseEvent;
+
/**
* TVScroller implements a simple vertical scroll bar.
*/
public final class TVScroller extends TWidget {
+ /**
+ * Value that corresponds to being on the top edge of the scroll bar.
+ */
+ private int topValue = 0;
+
+ /**
+ * Get the value that corresponds to being on the top edge of the scroll
+ * bar.
+ *
+ * @return the scroll value
+ */
+ public int getTopValue() {
+ return topValue;
+ }
+
+ /**
+ * Set the value that corresponds to being on the top edge of the scroll
+ * bar.
+ *
+ * @param topValue the new scroll value
+ */
+ public void setTopValue(final int topValue) {
+ this.topValue = topValue;
+ }
+
+ /**
+ * Value that corresponds to being on the bottom edge of the scroll bar.
+ */
+ private int bottomValue = 100;
+
+ /**
+ * Get the value that corresponds to being on the bottom edge of the
+ * scroll bar.
+ *
+ * @return the scroll value
+ */
+ public int getBottomValue() {
+ return bottomValue;
+ }
+
+ /**
+ * Set the value that corresponds to being on the bottom edge of the
+ * scroll bar.
+ *
+ * @param bottomValue the new scroll value
+ */
+ public void setBottomValue(final int bottomValue) {
+ this.bottomValue = bottomValue;
+ }
+
+ /**
+ * Current value of the scroll.
+ */
+ private int value = 0;
+
+ /**
+ * Get current value of the scroll.
+ *
+ * @return the scroll value
+ */
+ public int getValue() {
+ return value;
+ }
+
+ /**
+ * Set current value of the scroll.
+ *
+ * @param value the new scroll value
+ */
+ public void setValue(final int value) {
+ this.value = value;
+ }
+
+ /**
+ * The increment for clicking on an arrow.
+ */
+ private int smallChange = 1;
+
+ /**
+ * Set the increment for clicking on an arrow.
+ *
+ * @param smallChange the new increment value
+ */
+ public void setSmallChange(final int smallChange) {
+ this.smallChange = smallChange;
+ }
+
+ /**
+ * The increment for clicking in the bar between the box and an arrow.
+ */
+ private int bigChange = 20;
+
+ /**
+ * Set the increment for clicking in the bar between the box and an
+ * arrow.
+ *
+ * @param bigChange the new increment value
+ */
+ public void setBigChange(final int bigChange) {
+ this.bigChange = bigChange;
+ }
+
+ /**
+ * When true, the user is dragging the scroll box.
+ */
+ private boolean inScroll = false;
+
+ /**
+ * Public constructor.
+ *
+ * @param parent parent widget
+ * @param x column relative to parent
+ * @param y row relative to parent
+ * @param width height of scroll bar
+ */
+ public TVScroller(final TWidget parent, final int x, final int y,
+ final int height) {
+
+ // Set parent and window
+ super(parent);
+
+ setX(x);
+ setY(y);
+ setHeight(height);
+ setWidth(1);
+ }
+
+ /**
+ * Compute the position of the scroll box (a.k.a. grip, thumb).
+ *
+ * @param Y position of the box, between 1 and height - 2
+ */
+ private int boxPosition() {
+ return (getHeight() - 3) * (value - topValue) / (bottomValue - topValue) + 1;
+ }
+
+ /**
+ * Draw a vertical scroll bar.
+ */
+ @Override
+ public void draw() {
+ CellAttributes arrowColor = getTheme().getColor("tscroller.arrows");
+ CellAttributes barColor = getTheme().getColor("tscroller.bar");
+ getScreen().putCharXY(0, 0, GraphicsChars.CP437[0x1E], arrowColor);
+ getScreen().putCharXY(0, getHeight() - 1, GraphicsChars.CP437[0x1F],
+ arrowColor);
+
+ // Place the box
+ if (bottomValue > topValue) {
+ getScreen().vLineXY(0, 1, getHeight() - 2,
+ GraphicsChars.CP437[0xB1], barColor);
+ getScreen().putCharXY(0, boxPosition(), GraphicsChars.BOX,
+ arrowColor);
+ } else {
+ getScreen().vLineXY(0, 1, getHeight() - 2, GraphicsChars.HATCH,
+ barColor);
+ }
+
+ }
+
+ /**
+ * Perform a small step change up.
+ */
+ public void decrement() {
+ if (bottomValue == topValue) {
+ return;
+ }
+ value -= smallChange;
+ if (value < topValue) {
+ value = topValue;
+ }
+ }
+
+ /**
+ * Perform a small step change down.
+ */
+ public void increment() {
+ if (bottomValue == topValue) {
+ return;
+ }
+ value += smallChange;
+ if (value > bottomValue) {
+ value = bottomValue;
+ }
+ }
+
+ /**
+ * Perform a big step change up.
+ */
+ public void bigDecrement() {
+ if (bottomValue == topValue) {
+ return;
+ }
+ value -= bigChange;
+ if (value < topValue) {
+ value = topValue;
+ }
+ }
+
+ /**
+ * Perform a big step change down.
+ */
+ public void bigIncrement() {
+ if (bottomValue == topValue) {
+ return;
+ }
+ value += bigChange;
+ if (value > bottomValue) {
+ value = bottomValue;
+ }
+ }
+
+ /**
+ * Go to the top edge of the scroller.
+ */
+ public void toTop() {
+ value = topValue;
+ }
+
+ /**
+ * Go to the bottom edge of the scroller.
+ */
+ public void toBottom() {
+ value = bottomValue;
+ }
+
+ /**
+ * Handle mouse button releases.
+ *
+ * @param mouse mouse button release event
+ */
+ @Override
+ public void onMouseUp(final TMouseEvent mouse) {
+ if (bottomValue == topValue) {
+ return;
+ }
+
+ if (inScroll) {
+ inScroll = false;
+ return;
+ }
+
+ if ((mouse.getX() == 0)
+ && (mouse.getY() == 0)
+ ) {
+ // Clicked on the top arrow
+ decrement();
+ return;
+ }
+
+ if ((mouse.getX() == 0)
+ && (mouse.getY() == getHeight() - 1)
+ ) {
+ // Clicked on the bottom arrow
+ increment();
+ return;
+ }
+
+ if ((mouse.getX() == 0)
+ && (mouse.getY() > 0)
+ && (mouse.getY() < boxPosition())
+ ) {
+ // Clicked between the top arrow and the box
+ value -= bigChange;
+ if (value < topValue) {
+ value = topValue;
+ }
+ return;
+ }
+
+ if ((mouse.getX() == 0)
+ && (mouse.getY() > boxPosition())
+ && (mouse.getY() < getHeight() - 1)
+ ) {
+ // Clicked between the box and the bottom arrow
+ value += bigChange;
+ if (value > bottomValue) {
+ value = bottomValue;
+ }
+ return;
+ }
+ }
+
+ /**
+ * Handle mouse movement events.
+ *
+ * @param mouse mouse motion event
+ */
+ @Override
+ public void onMouseMotion(final TMouseEvent mouse) {
+ if (bottomValue == topValue) {
+ return;
+ }
+
+ if ((mouse.getMouse1()) &&
+ (inScroll) &&
+ (mouse.getY() > 0) &&
+ (mouse.getY() < getHeight() - 1)
+ ) {
+ // Recompute value based on new box position
+ value = (bottomValue - topValue) * (mouse.getY()) / (getHeight() - 3) + topValue;
+ return;
+ }
+
+ inScroll = false;
+ }
+
+ /**
+ * Handle mouse press events.
+ *
+ * @param mouse mouse button press event
+ */
+ @Override
+ public void onMouseDown(final TMouseEvent mouse) {
+ if (bottomValue == topValue) {
+ return;
+ }
+
+ if ((mouse.getX() == 0)
+ && (mouse.getY() == boxPosition())
+ ) {
+ inScroll = true;
+ return;
+ }
+ }
+
}
git://git.nikiroo.be / fanfix.git / blobdiff