*/
package jexer;
+import jexer.bits.CellAttributes;
+import jexer.bits.GraphicsChars;
+import jexer.event.TMouseEvent;
+
/**
* THScroller implements a simple horizontal scroll bar.
*/
public final class THScroller extends TWidget {
+ /**
+ * Value that corresponds to being on the left edge of the scroll bar.
+ */
+ private int leftValue = 0;
+
+ /**
+ * Get the value that corresponds to being on the left edge of the scroll
+ * bar.
+ *
+ * @return the scroll value
+ */
+ public int getLeftValue() {
+ return leftValue;
+ }
+
+ /**
+ * Set the value that corresponds to being on the left edge of the
+ * scroll bar.
+ *
+ * @param leftValue the new scroll value
+ */
+ public void setLeftValue(final int leftValue) {
+ this.leftValue = leftValue;
+ }
+
+ /**
+ * Value that corresponds to being on the right edge of the scroll bar.
+ */
+ private int rightValue = 100;
+
+ /**
+ * Get the value that corresponds to being on the right edge of the
+ * scroll bar.
+ *
+ * @return the scroll value
+ */
+ public int getRightValue() {
+ return rightValue;
+ }
+
+ /**
+ * Set the value that corresponds to being on the right edge of the
+ * scroll bar.
+ *
+ * @param rightValue the new scroll value
+ */
+ public void setRightValue(final int rightValue) {
+ this.rightValue = rightValue;
+ }
+
+ /**
+ * 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 THScroller(final TWidget parent, final int x, final int y,
+ final int width) {
+
+ // Set parent and window
+ super(parent);
+
+ setX(x);
+ setY(y);
+ setHeight(1);
+ setWidth(width);
+ }
+
+ /**
+ * Compute the position of the scroll box (a.k.a. grip, thumb).
+ *
+ * @return Y position of the box, between 1 and width - 2
+ */
+ private int boxPosition() {
+ return (getWidth() - 3) * (value - leftValue) / (rightValue - leftValue) + 1;
+ }
+
+ /**
+ * Draw a horizontal scroll bar.
+ */
+ @Override
+ public void draw() {
+ CellAttributes arrowColor = getTheme().getColor("tscroller.arrows");
+ CellAttributes barColor = getTheme().getColor("tscroller.bar");
+ getScreen().putCharXY(0, 0, GraphicsChars.CP437[0x11], arrowColor);
+ getScreen().putCharXY(getWidth() - 1, 0, GraphicsChars.CP437[0x10],
+ arrowColor);
+
+ // Place the box
+ if (rightValue > leftValue) {
+ getScreen().hLineXY(1, 0, getWidth() - 2, GraphicsChars.CP437[0xB1],
+ barColor);
+ getScreen().putCharXY(boxPosition(), 0, GraphicsChars.BOX,
+ arrowColor);
+ } else {
+ getScreen().hLineXY(1, 0, getWidth() - 2, GraphicsChars.HATCH,
+ barColor);
+ }
+
+ }
+
+ /**
+ * Perform a small step change left.
+ */
+ public void decrement() {
+ if (leftValue == rightValue) {
+ return;
+ }
+ value -= smallChange;
+ if (value < leftValue) {
+ value = leftValue;
+ }
+ }
+
+ /**
+ * Perform a small step change right.
+ */
+ public void increment() {
+ if (leftValue == rightValue) {
+ return;
+ }
+ value += smallChange;
+ if (value > rightValue) {
+ value = rightValue;
+ }
+ }
+
+ /**
+ * Handle mouse button releases.
+ *
+ * @param mouse mouse button release event
+ */
+ @Override
+ public void onMouseUp(final TMouseEvent mouse) {
+
+ if (inScroll) {
+ inScroll = false;
+ return;
+ }
+
+ if (rightValue == leftValue) {
+ return;
+ }
+
+ if ((mouse.getX() == 0)
+ && (mouse.getY() == 0)
+ ) {
+ // Clicked on the left arrow
+ decrement();
+ return;
+ }
+
+ if ((mouse.getY() == 0)
+ && (mouse.getX() == getWidth() - 1)
+ ) {
+ // Clicked on the right arrow
+ increment();
+ return;
+ }
+
+ if ((mouse.getY() == 0)
+ && (mouse.getX() > 0)
+ && (mouse.getX() < boxPosition())
+ ) {
+ // Clicked between the left arrow and the box
+ value -= bigChange;
+ if (value < leftValue) {
+ value = leftValue;
+ }
+ return;
+ }
+
+ if ((mouse.getY() == 0)
+ && (mouse.getX() > boxPosition())
+ && (mouse.getX() < getWidth() - 1)
+ ) {
+ // Clicked between the box and the right arrow
+ value += bigChange;
+ if (value > rightValue) {
+ value = rightValue;
+ }
+ return;
+ }
+ }
+
+ /**
+ * Handle mouse movement events.
+ *
+ * @param mouse mouse motion event
+ */
+ @Override
+ public void onMouseMotion(final TMouseEvent mouse) {
+
+ if (rightValue == leftValue) {
+ inScroll = false;
+ return;
+ }
+
+ if ((mouse.getMouse1())
+ && (inScroll)
+ && (mouse.getX() > 0)
+ && (mouse.getX() < getWidth() - 1)
+ ) {
+ // Recompute value based on new box position
+ value = (rightValue - leftValue) * (mouse.getX()) / (getWidth() - 3) + leftValue;
+ return;
+ }
+ inScroll = false;
+ }
+
+ /**
+ * Handle mouse button press events.
+ *
+ * @param mouse mouse button press event
+ */
+ @Override
+ public void onMouseDown(final TMouseEvent mouse) {
+ if (rightValue == leftValue) {
+ inScroll = false;
+ return;
+ }
+
+ if ((mouse.getY() == 0)
+ && (mouse.getX() == boxPosition())
+ ) {
+ inScroll = true;
+ return;
+ }
+
+ }
+
}
git://git.nikiroo.be / nikiroo-utils.git / blobdiff