How to create scrollbar in Canvas

[elenora]

Hi,
I had create a rectangle in Canvas like the textfield and now I can print my input in that rectangle, I want that how can I write the input when it's size is bigger than the rectangle! I want that when it's size is bigger than the rectangle the remain of my input must be shown and the input which I wrote earlier must be shifted! actualy I want to scroll my input in the rctangle, How can I do it? Could anyone show me sample code for it please?

[grahamhughes]

Make sure that, on every paint(), you are drawing all the text. Then, if you want it to move up, just draw it at a smaller "y" position. To avoid any text appearing outside the rectangle, use setClip() to the size of the rectangle.

Graham.

[elenora]

Hi,
I want to draw a cursor in the rectangle which I described about it earlier and the cursor must move when I enter an input or erase the input, I had wrote some code like below but it doesn’t draw the cursor, could you help me How can I solve my problem please?

public class MyTextBox{
private int cursorplace=0;
private char cursor[];
protected MyTextBox()
{
cursor=new char[100];
}

protected void paint(Graphics g, int width, int height)
{
g.setColor(0xffffff);
g.fillRect(0, 0, width, height);
g.setColor(0, 0, 0);
g.drawRoundRect(20, 40, 190, 40, 30, 20);
g.setColor(0xbfd4f6);
g.fillRoundRect(20, 40, 190, 40, 30, 20);
g.drawChars(cursor, 0, 100, width - 40, 55, Graphics.RIGHT| Graphics.BOTTOM);}

protected void keyPressed(int keyCode)
{
cursor[cursorplace]='_';
if(keyCode==-4){
shiftLeft();
}
if(keyCode==-3){
shiftRight();
}
long currentTime = System.currentTimeMillis();
int pressedKeyNum = getNum(keyCode);
if( pressedKeyNum >= 0 && pressedKeyNum <= 9 ) {
if(keyCode == this.lastKeyStroke && currentTime - this.lastKeyStrokeTime < MIN_STROKE_TIME)
{
cursorplace++;
curser[cursorplace]='_';
this.text = this.text.substring(0, this.text.length() - 1);
this.text += KEY_MAP[pressedKeyNum][this.lastKeyStrokeIndex];
this.lastKeyStrokeIndex++;
}
else
{
cursorplace++;
cursor[cursorplace]='_';
this.text += KEY_MAP[pressedKeyNum][0];
this.lastKeyStrokeIndex = 1;
}

//some code
}

[grahamhughes]

It looks like you're drawing a filled-rectangle, then drawing characters on top in the same colour?

Graham.

[elenora]

thank you for your reply Mr. Graham, I added g.setColor(0, 0, 0);
before g.drawChars but it doesn't work yet! to scrolling the input in the rectangle I worte some code like below but when i scroll the input with Canvas.Right the String which I inserted after scrolling will be seprated to characters! Could you help me to solve it please?How could I shift the String when I click on Canvas.Right?


public void copyStr(){

tchar=this.text.toCharArray();
copy=text.length()-1;
textchar[cp]=tchar[copy];
t[p]=textchar[cp];
cp++;
p++;
if(text.length()>=9){

shiftRight();

}
}
public void shiftRight(){
int m=0;
String temp;
char []te;
for (int i=10;i<this.text.length()-1;i++){
t[i-1]=t[i];
}
for(int i=10;i<this.text.length()-1;i++){
textchar[m]=t[i];
m++;
}
text=new String(textchar);
}

protected void keyPressed(int keyCode)
{
if(keyCode==-4){
shiftRight();
}

long currentTime = System.currentTimeMillis();
int pressedKeyNum = getNum(keyCode);
if( pressedKeyNum >= 0 && pressedKeyNum <= 9 ) {
if(keyCode == this.lastKeyStroke && currentTime - this.lastKeyStrokeTime < MIN_STROKE_TIME)
{
cursorplace++;
cursor[cursorplace]='_';
this.text = this.text.substring(0, this.text.length() - 1);
this.text += KEY_MAP[pressedKeyNum][this.lastKeyStrokeIndex];
this.lastKeyStrokeIndex++;
copyStr();
}

else
{
this.text += KEY_MAP[pressedKeyNum][0];
this.lastKeyStrokeIndex = 1;
copyStr();
}

if(this.lastKeyStrokeIndex >= KEY_MAP[pressedKeyNum].length)
{
this.lastKeyStrokeIndex = 0;
}
else
{
if( pressedKeyNum == 10 ) {
this.remove();
}
}
this.lastKeyStroke = keyCode;
this.lastKeyStrokeTime = System.currentTimeMillis();
}

}