все очень просто...
P.S. честно признаюсь прорисовку скрола взял из библиотеки J4ME. можешь на нее посмотреть - открытый код, нормальная лицензия
| Код |
import javax.microedition.lcdui.*;
public class DrawList extends Canvas implements CommandListener {
private Command exitCommand = new Command("Выход", Command.EXIT, 0);
private Command backCommand = new Command("Назад", Command.BACK, 0);
private int index = 0;
private int hStr = 20;
private int indexOff = 0;
private int displayCount = 0;
private int topPadding = 0;
private String str[] = { "1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13", "14", "15", "16",
"17", "18", "19", "20", "21", "22", "23", "24", "25", "26", "27", "28", "29", "30", "31", "32", "33", "34",
"35", "36", "37", "38", "39" };
public DrawList() {
displayCount = getHeight() / hStr;
topPadding = (getHeight() % hStr) / 2;
}
public void paint(Graphics g) {
drawBackground(g);
int yPosStr = topPadding;
for (int i = indexOff; i < indexOff + displayCount && i < str.length; i++) {
if (i == index) {
drawSelectedLabel(g, 0, yPosStr, str[i], 5, 5);
} else {
drawLabel(g, 0, yPosStr, str[i], 5, 5);
}
yPosStr += hStr;
}
if(isScroolNeed())
VerticalScrollBar.paintVerticalScrollbar(g, 0, topPadding, g.getClipWidth(), g.getClipHeight() - 2 * topPadding, indexOff * hStr, str.length * hStr);
}
private void drawBackground(Graphics g) {
int width = g.getClipWidth();
int height = g.getClipHeight();
g.setColor(255, 255, 255);
g.fillRect(0, 0, width, height);
}
/**
*
* @param g
* @param x
* @param y
* @param label
* @param padding -
* отступ текста
* @param margin -
* отступ от края экрана
*/
private void drawSelectedLabel(Graphics g, int x, int y, String label, int padding, int margin) {
x += margin;
g.setColor(0, 255, 0);
int width = g.getClipWidth();
if(isScroolNeed()){
width -= VerticalScrollBar.SCROLL_WIDTH;
}
g.fillRect(x, y, width - x - margin, hStr);
g.setColor(255, 255, 255);
g.drawString(label, x + padding, y, Graphics.TOP | Graphics.LEFT);
}
private void drawLabel(Graphics g, int x, int y, String label, int padding, int margin) {
g.setColor(0x373c3e);
g.drawString(label, x + margin + padding, y, Graphics.TOP | Graphics.LEFT);
}
/*
* public void drawScroll(Graphics g, int borderClr, int barCrl, int
* scrollClr, int yPosScrl) { g.setColor(borderClr); g.drawRect(width - 8,
* 0, width, height); g.setColor(barCrl); g.fillRect(width - 7, 0, width,
* height); g.setColor(scrollClr); g.fillRect(width - 7, yPosScroll, width,
* hScroll); }
*/
public void keyPressed(int keyCode) {
int action = getGameAction(keyCode); // Заносим в переменную код
// нажатой
// кнопки
switch (action) {
case Canvas.DOWN:
moveDown();
break;
case Canvas.UP:
moveUp();
break;
case Canvas.FIRE:
// Tcity.getInstance().showKey(index);
break;
}
}
protected void keyRepeated(int keyCode) {// если держат нажатой кнопку.
int action = getGameAction(keyCode);
switch (action) {
case Canvas.DOWN:
moveDown();
break;
case Canvas.UP:
moveUp();
break;
}
}
public void commandAction(Command c, Displayable d) {
}
private void moveUp() {
if (index == 0) {
indexOff = str.length - displayCount;
index = str.length - 1;
} else {
if (index == indexOff) {
indexOff--;
}
index--;
}
repaint();
}
private void moveDown() {
if (index == str.length - 1) {
indexOff = 0;
index = 0;
} else {
if (index == indexOff + displayCount - 1) {
indexOff++;
}
index++;
}
repaint();
}
private boolean isScroolNeed(){
return str.length > displayCount;
}
private static class VerticalScrollBar {
public static final int SCROLL_WIDTH = 6;
private static final int SCROLL_BORDER_COLOR = 0xff0000;
private static final int SCROLL_BG_COLOR = 0x0000ff;
private static final int SCROLL_TRACKBAR_COLOR = 0x00ff00;
public static void paintVerticalScrollbar(Graphics g, int x, int y, int width, int height, int offset, int formHeight) {
// Make the scrollbar as wide as the rounding diameter.
int left = x + width - SCROLL_WIDTH;
// Draw the scrollbar background.
paintScrollbarBackground(g, left, y, SCROLL_WIDTH, height);
// Draw an edge to the scrollbar.
g.setColor(SCROLL_BORDER_COLOR);
g.drawLine(left, y, left, y + height);
// Calculate the height of the trackbar.
int scrollableHeight = formHeight - height;
double trackbarPercentage = (double) height / (double) formHeight;
int trackbarHeight = round(height * trackbarPercentage);
trackbarHeight = Math.max(trackbarHeight, 2 * SCROLL_WIDTH);
// Calculate the range and location of the trackbar.
// The scrollbar doesn't actually go from 0% to 100%. The top
// is actually 1/2 the height of the trackbar from the top of
// the screen. The bottom is 1/2 the height from the bottom.
int rangeStart = trackbarHeight / 2;
int range = height - 2 * rangeStart;
double offsetPercentage = (double) offset / (double) scrollableHeight;
int center = y + rangeStart + round(offsetPercentage * range);
// Draw the trackbar.
paintTrackbar(g, left, center - rangeStart, SCROLL_WIDTH, trackbarHeight);
}
protected static void paintTrackbar(Graphics g, int x, int y, int width, int height) {
// This code would paint the scrollbar a solid background.
g.setColor(SCROLL_TRACKBAR_COLOR);
g.fillRect(x, y, width, height);
}
protected static void paintScrollbarBackground(Graphics g, int x, int y, int width, int height) {
g.setColor(SCROLL_BG_COLOR);
g.fillRect(x, y, width, height);
}
public static int round(double a) {
return (int) Math.floor(a + 0.5);
}
}
}
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и я никак въехать не могу как доделать управление списком.
спасибо огромнейшее. имено то что нужно было. в коде пока не разобрался, как время будет буду разбирать всё детально!!! 