// cargo run --example canvas_scrolling

use std::os::raw::c_double;
use tcl::*;
use tk::*;
use tk::canvas::*;
use tk::cmd::*;

fn main() -> TkResult<()> {
    let tk = make_tk!()?;
    let root = tk.root();

    let canvas = root
        .add_canvas( "canvas" -scrollregion("0 0 1000 1000") -yscrollcommand(".v set") -xscrollcommand(".h set") )?
        .grid( -sticky("nwes") -column(0i32) -row(0i32) )?;

    root.grid_columnconfigure( 0, -weight(1) )?;
    root.grid_rowconfigure( 0, -weight(1) )?;

    let _h = root
        .add_ttk_scrollbar( "h" -orient("horizontal") -command(".canvas xview") )?
        .grid( -column(0) -row(1) -sticky("we") )?;

    let _v = root
        .add_ttk_scrollbar( "v" -orient("vertical") -command(".canvas yview") )?
        .grid( -column(1) -row(0) -sticky("ns") )?;

    Widget::bind( &canvas, event::button_press_1(),
        "set lastx [.canvas canvasx %x]; set lasty [.canvas canvasy %y]" )?;
    Widget::bind( &canvas, event::button_1().motion(), tclosure!( tk,
        |evt_x:c_double, evt_y:c_double| -> TkResult<()> {
            let x = canvas.canvasx( evt_x, None )?;
            let y = canvas.canvasy( evt_y, None )?;

            let last_x = tk.get_double("lastx")?;
            let last_y = tk.get_double("lasty")?;
            let color = tk.get("color")?;

            canvas.dtag( item_tag( "all" ),
                Some( ItemTag( "paletteSelected".to_owned() )))?;
            canvas.itemconfigure( item_tag( "palette" ),
                -outline("white") )?;
            canvas.addtag( "paletteSelected",
                SearchSpec::WithTag(
                    item_tag( &format!( "palette{}", color.clone().get_string() )).into() ))?;
            canvas.itemconfigure( item_tag( "paletteSelected" ), -outline("#999999") )?;

            canvas.create_line( &[ (last_x,last_y), (x,y) ],
                -fill(color) -width(5) -tags("currentline") )?;

            tk.set( "lastx", x );
            tk.set( "lasty", y );
            Ok(())
        }
    ))?;

    Widget::bind(
        &canvas,
        event::button_1().button_release(),
        tclosure!( tk, || ->TkResult<()> {
            Ok( canvas.itemconfigure( item_tag( "currentline" ), -width(1) )? )
        })
    )?;

    let id = canvas.create_rectangle( 10.0, 10.0, 30.0, 30.0,
        -fill("red") -tags("palette palettered") )?;
    canvas.bind( id,
        event::button_press_1(),
        tclosure!( tk, || { tk.set( "color", "red" ); Ok(()) }))?;

    let id = canvas.create_rectangle( 10.0, 35.0, 30.0, 55.0,
        -fill("blue") -tags("palette paletteblue") )?;
    canvas.bind( id,
        event::button_press_1(),
        tclosure!( tk, || { tk.set( "color", "blue" ); Ok(()) }))?;

    let id = canvas.create_rectangle( 10.0, 60.0, 30.0, 80.0,
        -fill("black") -tags("palette paletteblack paletteSelected") )?;
    canvas.bind( id,
        event::button_press_1(),
        tclosure!( tk, || { tk.set( "color", "black" ); Ok(()) }))?;

    tk.set( "color", "black" );
    canvas.itemconfigure( item_tag( "palette" ), -width(5) )?;

    Ok( main_loop() )
}