mouse move selection retention

Programming Questions

helmutapp..

mouse move selection retention

in Programming Questions • 9 months ago

I have a simple mouse drag setup in my program, that can move objects from an array of a slightly complicated class...

Setup+++++++++++++++++++++++

int sel=0;

Draw++++++++++++++++++++++++

Rect dragR = (Rect) rects.get(i);

if (mouseX <= (dragR.pos.x + (sWidth/2)) && mouseX >= (dragR.pos.x - (sWidth/2)) && mouseY <= (dragR.pos.y + (dragR.tHeight/2)) && mouseY >= (dragR.pos.y - (dragR.tHeight/2))){

sel=1;

if (dragging){

dragR.pos.x=mouseX;

dragR.pos.y=mouseY;

}

else {

sel=0;

}

++++++++++++++++++++++++++++

void mouseDragged(){

dragging=true;

}

void mouseReleased(){

dragging=false;

}

Obviously, this does not work when the mouse strays away from the object.

Is there a simple way to 'lock down' the selection to keep the move active when the mouse strays?

I've looked at other code, and it is specific to their setup. What would be ideal I think is some sort of boolean that keeps the object selected if the mouse is not released after initial good selection.

If anyone can give me hint, I'd be happy!

Replies(10)

quarks

Re: mouse move selection retention

9 months ago

Try doing it this way.

//Setup+++++++++++++++++++++++
int sel=0;

//Draw++++++++++++++++++++++++
Rect dragR = (Rect) rects.get(i);

if (dragging) {
dragR.pos.x=mouseX;
dragR.pos.y=mouseY;
}
else {
sel=0;
}
//++++++++++++++++++++++++++++
void mousePressed() {
if (mouseX <= (dragR.pos.x + (sWidth/2)) && mouseX >= (dragR.pos.x - (sWidth/2)) && mouseY <= (dragR.pos.y + (dragR.tHeight/2)) && mouseY >= (dragR.pos.y - (dragR.tHeight/2))) {
    dragging=true;
    sel = 1;
}
else
    sel = 0;
}

void mouseDragged() {
dragging=true;
}

void mouseReleased() {
dragging=false;
}

helmutapp..

Re: mouse move selection retention

9 months ago

Thanks Quarks,

Tried that, but the values for the object are only in Draw as they they are in an array.

quarks

Re: mouse move selection retention

9 months ago

I assume that rects is an ArrayList declared globally in which case change mousePressed() to

void mousePressed() {
Rect dragR = (Rect) rects.get(i);
if (mouseX <= (dragR.pos.x + (sWidth/2)) && mouseX >= (dragR.pos.x - (sWidth/2)) && mouseY <= (dragR.pos.y + (dragR.tHeight/2)) && mouseY >= (dragR.pos.y - (dragR.tHeight/2))) {
    dragging=true;
    sel = 1;
}
else
    sel = 0;
}

helmutapp..

Re: mouse move selection retention

9 months ago

Thanks again,

Didn't think that was possible, as you have to do a for loop to get the i in;

Rect dragR = (Rect) rects.get(i);

int selHold;

Draw

if (selHold==1 && dragging){

dragR.pos.x=mouseX;

dragR.pos.y=mouseY;

}

void mousePressed(){

for( int i=0; i < rects.size(); i++ ){

Rect dragR = (Rect) rects.get(i);

if (mouseX <= (dragR.pos.x + (sWidth/2)) && mouseX >= (dragR.pos.x - (sWidth/2)) && mouseY <= (dragR.pos.y + (dragR.tHeight/2)) && mouseY >= (dragR.pos.y - (dragR.tHeight/2))){

selHold=1;

dragging=true;

}

//else {

//selHold=0;

//}

}

void mouseDragged(){

dragging=true;

}

void mouseReleased(){

dragging=false;

selHold=0;

}

Although it does solve the problem of not having to have the mouse over them to move, it moves all the rects (well, half are made to orbit another half) ! :)

If I activate the else selHold=0 in mousePressed, the mouse cannot drag.

The only other thing I can think of is that there is a Push and Pop matrix in the Draw, as the Rects are actually boxes....

PhiLho

Re: mouse move selection retention

9 months ago

For what it is worth, my Handles sketch is showing, with lot of comments, how to manage drag'n'drop of elements, without the pitfalls you mention (dragging several elements at once, etc.).
Perhaps it can give you some ideas.

quarks

Re: mouse move selection retention

9 months ago

Define dragR as a global variable with
Rect dragR;

then modify mousePressed to use this variable i.e.

void mousePressed(){

for( int i=0; i < rects.size(); i++ ){

dragR = (Rect) rects.get(i);

if (mouseX <= (dragR.pos.x + (sWidth/2)) && mouseX >= (dragR.pos.x - (sWidth/2)) && mouseY <= (dragR.pos.y + (dragR.tHeight/2)) && mouseY >= (dragR.pos.y - (dragR.tHeight/2))){

selHold=1;

dragging=true;

}

//else {

//selHold=0;

//}

}

}

And remove from draw() the line
Rect dragR = (Rect) rects.get(i);

helmutapp..

Re: mouse move selection retention

9 months ago

Thanks guys,

I had a look at that, and the PhiLho solution seems the right long term fix, though it would involve some restructuring on my code, so I will leave that for later.

If I could implement a dirty fix now, that would suit me, as the code has a full rewrite date scheduled in the future.

Quarks, the idea you have nearly works, though I feel it may not go all the way.

when used, the last rect works as desired, but none of the rest.

I cannot decide if this is something that could come with one or two tweaks, or if the full rewrite is required.

If you have any final thoughts, please do let me know.

Much appreciated.....

helmutapp..

Re: mouse move selection retention

8 months ago

Hey guys,

I found the solution that works with my code, and thought I would share it and give closure :)

The thing that cracked it was simplicity (later I can complicate it up)

In global var I just have a boolean called press.

boolean press=false;

//+++++++++++++++++++++++++++++++++++++++++++++++

In void draw I have this: (to iterate)

Rect dragR = (Rect) rects.get(i);

if (dragR.sel>=1){

dragR.pos.x=mouseX;

dragR.pos.y=mouseY;

}

//+++++++++++++++++++++++++++++++++++++++++++++++

also in main body;

void mouseReleased(){

press=false;

}

void mousePressed(){

press=true;

}

//+++++++++++++++++++++++++++++++++++++++++++++++

Then in the Rects class I have a variable for selection;

int sel=0;

And the code for selection;

void display(){

<Snip>

if (mouseX <= (pos.x + (sWidth/2)) && mouseX >= (pos.x - (sWidth/2)) && mouseY <= (pos.y + (tHeight/2)) && mouseY >= (pos.y - (tHeight/2)) && mousePressed){

sel=sel+1;

}

if (press==false){

sel=0;

}

+++++++++++++++++++++++++++++++++++++++++++++++

And, Violin!,....The sel stays selected until the mouse is released, even if the mouse moves faster than the rect. I thought there was some solution for it. For me the breakthrough was putting the sel in the class and accessing the press from the class. I might not need to have the sel be a int, I'll test it with a boolean.

I'm sure I'll find something broken soon, but it works for now! Thanks quarks and PhiLho......

helmutapp..

Re: mouse move selection retention

8 months ago

Ok, got rid of the press boolean and just use !mousePressed now :)

helmutapp..

Re: mouse move selection retention

8 months ago

yup, main code is;

+++++++++++++++++++++++++++++++++++

void draw(){

<Snip>

Rect dragR = (Rect) rects.get(i);

if (dragR.sel){

dragR.pos.x=mouseX;

dragR.pos.y=mouseY;

}

+++++++++++++++++++++++++++++++++++

Rect Class is

boolean sel=false;

void display(){

<Snip>

if (mouseX <= (pos.x + (sWidth/2)) && mouseX >= (pos.x - (sWidth/2)) && mouseY <= (pos.y + (tHeight/2)) && mouseY >= (pos.y - (tHeight/2)) && mousePressed){

sel=true;

}

if (!mousePressed){

sel=false;

}

++++++++++++++++++++++++++++++++

Its easy when you know it :)

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