done open, save, undo and redo (can make better )

Contributed Library Questions

jane38

done open, save, undo and redo (can make better )

in Contributed Library Questions • 8 months ago

I was trying to achieve open and save functions frankly I did not understand selectinput and selectoutput

but thanks to it being made easier by G4P I did it

as for undo and redo I used an PImage arraylist to get an instant of the canvas after each action

all work,

I have two small question

I wanna know

if undo redo can be made better since the sizeof the arraylist is how many actions have been taken

and that can get quite big

the other is if I can change the default image format to save in.

the default is tiff.

during saving you can specify format such as myimage.jpg

and it will save in jpg

import g4p_controls.*;
GImageButton btnInput, btnOutput;
int lineToolX, lineToolY;
PImage save;
PImage screen;
ArrayList<PImage> screens;
int counter=1;
int redocounter=0;
void setup() {
size(400,400);
background(255);
frameRate(200);
loadPixels();
screens=new ArrayList();
//PApplet.useNativeSelect=true;
String[] files;
files = new String[] {
"openB.png", "openA.png"
};
btnInput = new GImageButton(this, 0,0,files);
files = new String[] {
"saveB.png", "saveA.png"
};
btnOutput = new GImageButton(this, 0, 57, files);
}
void draw()
{
rect(0,57*2,57,57*2);
fill(200);
//used as undo button
rect(0,57*2,57,57);
/*if(mousePressed&&mouseX<57&&mouseY>(57*2)&&mouseY<(57*3))
{
--counter;
set(57,57,screens.get(counter));
}*/
fill(100);
//used as undo button
rect(0,57*3,57,57);
if(mousePressed&&mouseX<57&&mouseY>(57*2)&&mouseY<(57*3))
{}
if(mousePressed&&mouseX>57){
stroke(0);
strokeWeight(3);
noFill();
line(pmouseX,pmouseY, mouseX, mouseY);
}
}
void mousePressed()
{
if(mouseX<57&&mouseY>(57*2)&&mouseY<(57*3)&&mousePressed)
{
counter++;
if((screens.size()-counter)>=0){
set(57,57,screens.get(screens.size()-counter));
println(screens.size()+" "+counter+" "+(screens.size()-counter));}
}
if(mouseX<57&&mouseY>(57*3)&&mouseY<(57*4)&&mousePressed)
{
if(counter>1){
counter--;
if((screens.size())!=counter){
set(57,57,screens.get(screens.size()-counter));
println(screens.size()+" "+counter+" "+(screens.size()-counter));} }
}
lineToolX = mouseX;
lineToolY = mouseY;
}
void mouseReleased() {
if(mouseX>57&&mouseY>57){
redocounter++;
screen=get(57,57,width,height);
screens.add(screen);
println(screens.size()+" "+counter);}
loadPixels();
}
// G4P code for folder and file dialogs
public void handleButtonEvents(GImageButton button, GEvent event) {
String fname;
// File input selection
if (button == btnInput) {
// Use file filter if possible
fname = G4P.selectInput("Open", "png,gif,jpg,jpeg", "Image files");
save = loadImage(fname);
set(0, 0, save);
loadPixels();
}
// File output selection
else if (button == btnOutput) {
fname = G4P.selectOutput("Save as");
save = get();
save.save(fname);
//lblFile.setText(fname);
}
}

Replies(3)

GoToLoop

Re: done open, save, undo and redo (can make better )

8 months ago

I wanna know if undo redo can be made better since the sizeof the arraylist is how many actions have been taken and that can get quite big

You may try out an ArrayDeque in place of an ArrayList.
An ArrayDeque can be used for queue & stack access.
But since undo & redo are stack type operations, here's a list of basic methods to use:

push() -> inserts an element in the beginning of the Deque.
pop() -> retrieves the 1st element, by removing it
peek() -> retrieves, but doesn't remove 1st element

You have to put a limit of how many undos are possible.
While limit is not reached, you just keep using push() to insert and pop() to undo.

But once limit is reached, from now on,
before using push(), use removeLast() to erase the oldest undo!

final static short maxUndos = 100;
final static Deque<PImage> screens = new ArrayDeque(maxUndos);

For an extra example see this post:
http://forum.processing.org/topic/drawing-a-trail-for-a-moving-object

Although it's about Queue access instead of Stack.

Well, that's what I know so far!

jane38

Re: done open, save, undo and redo (can make better )

8 months ago

truthfully this is the first time I heard of arraydeque the processing website has nothing on it

do you now where I can read about it

as for the example sadly it does not run no idea why

I noticed that you had to import java.util

so no problem there

the problem is this line

tt = trails.remove();

it says cannot convert from object to sketch.PointXY

GoToLoop

Re: done open, save, undo and redo (can make better )

8 months ago

So sorry about the error!

I keep forgetting that when posting code here using HTML formatting,
it swallows the generics type between angle brackets!

Seek out this code line @ the top :

final static Queue trails = new ArrayDeque(maxTrailPoints);

And insert the following after Queue -> <PointXY>
So it knows which type of object is stored inside ArrayDeque trails

The import java.util.*; was in the very beginning of the code, but was commented out!

It's b/c it already works in my Processing v1.5.1 w/o it. However it's necessary for the newer betas and on!
That is so, b/c Processing only has official support for only a tiny spectrum of available Java classes!

Reference for interface Deque you can find @ the link below:
http://docs.oracle.com/javase/6/docs/api/java/util/Deque.html

Any further doubts, just ask!

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