/*************************************************************************/
/*  scroll_bar.cpp                                                       */
/*************************************************************************/
/*                       This file is part of:                           */
/*                           GODOT ENGINE                                */
/*                    http://www.godotengine.org                         */
/*************************************************************************/
/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur.                 */
/*                                                                       */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the       */
/* "Software"), to deal in the Software without restriction, including   */
/* without limitation the rights to use, copy, modify, merge, publish,   */
/* distribute, sublicense, and/or sell copies of the Software, and to    */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions:                                             */
/*                                                                       */
/* The above copyright notice and this permission notice shall be        */
/* included in all copies or substantial portions of the Software.       */
/*                                                                       */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
/*************************************************************************/
#include "scroll_bar.h"
#include "os/keyboard.h"
#include "print_string.h"
#include "os/os.h"
bool ScrollBar::focus_by_default=false;



void ScrollBar::set_can_focus_by_default(bool p_can_focus) {

	focus_by_default=p_can_focus;
}

void ScrollBar::_gui_input(InputEvent p_event) {


	switch(p_event.type) {

		case InputEvent::MOUSE_BUTTON: {

			const InputEventMouseButton &b=p_event.mouse_button;
			accept_event();

			if (b.button_index==5 && b.pressed) {

				//if (orientation==VERTICAL)
				//	set_val( get_val() + get_page() / 4.0 );
				//else
				set_value( get_value() + get_page() / 4.0 );
				accept_event();

			}

			if (b.button_index==4 && b.pressed) {

				//if (orientation==HORIZONTAL)
				//	set_val( get_val() - get_page() / 4.0 );
				//else
				set_value( get_value() - get_page() / 4.0  );
				accept_event();
			}

			if (b.button_index!=1)
				return;


			if (b.pressed) {


				double ofs = orientation==VERTICAL ? b.y : b.x ;
				Ref<Texture> decr = get_icon("decrement");
				Ref<Texture> incr = get_icon("increment");

				double decr_size = orientation==VERTICAL ? decr->get_height() : decr->get_width();
				double incr_size = orientation==VERTICAL ? incr->get_height() : incr->get_width();
				double grabber_ofs = get_grabber_offset();
				double grabber_size = get_grabber_size();
				double total = orientation==VERTICAL ? get_size().height : get_size().width;

				if (ofs < decr_size ) {

					set_value( get_value() - (custom_step>=0?custom_step:get_step()) );
					break;
				}

				if (ofs > total-incr_size ) {

					set_value( get_value() + (custom_step>=0?custom_step:get_step()) );
					break;
				}

				ofs-=decr_size;

				if ( ofs < grabber_ofs ) {

					set_value( get_value() - get_page() );
					break;

				}

				ofs-=grabber_ofs;

				if (ofs < grabber_size ) {

					drag.active=true;
					drag.pos_at_click=grabber_ofs+ofs;
					drag.value_at_click=get_unit_value();
					update();
				} else {


					set_value( get_value() + get_page() );
				}


			} else {

				drag.active=false;
				update();
			}

		} break;
		case InputEvent::MOUSE_MOTION: {

			const InputEventMouseMotion &m=p_event.mouse_motion;

			accept_event();


			if (drag.active) {

				double ofs = orientation==VERTICAL ? m.y : m.x ;
				Ref<Texture> decr = get_icon("decrement");

				double decr_size = orientation==VERTICAL ? decr->get_height() : decr->get_width();
				ofs-=decr_size;

				double diff = (ofs-drag.pos_at_click) / get_area_size();

				set_unit_value( drag.value_at_click + diff );
			} else {


				double ofs = orientation==VERTICAL ? m.y : m.x ;
				Ref<Texture> decr = get_icon("decrement");
				Ref<Texture> incr = get_icon("increment");

				double decr_size = orientation==VERTICAL ? decr->get_height() : decr->get_width();
				double incr_size = orientation==VERTICAL ? incr->get_height() : incr->get_width();
				double total = orientation==VERTICAL ? get_size().height : get_size().width;

				HiliteStatus new_hilite;

				if (ofs < decr_size ) {

					new_hilite=HILITE_DECR;

				} else if (ofs > total-incr_size ) {

					new_hilite=HILITE_INCR;

				} else {

					new_hilite=HILITE_RANGE;
				}

				if (new_hilite!=hilite) {

					hilite=new_hilite;
					update();

				}

			}
		} break;
		case InputEvent::KEY: {

			const InputEventKey &k=p_event.key;

			if (!k.pressed)
				return;

			switch (k.scancode) {

				case KEY_LEFT: {

					if (orientation!=HORIZONTAL)
						return;
					set_value( get_value() - (custom_step>=0?custom_step:get_step()) );

				} break;
				case KEY_RIGHT: {

					if (orientation!=HORIZONTAL)
						return;
					set_value( get_value() + (custom_step>=0?custom_step:get_step()) );

				} break;
				case KEY_UP: {

					if (orientation!=VERTICAL)
						return;

					set_value( get_value() - (custom_step>=0?custom_step:get_step()) );


				} break;
				case KEY_DOWN: {

					if (orientation!=VERTICAL)
						return;
					set_value( get_value() + (custom_step>=0?custom_step:get_step()) );

				} break;
				case KEY_HOME: {

					set_value( get_min() );

				} break;
				case KEY_END: {

					set_value( get_max() );

				} break;

			} break;
		}
	}
}

void ScrollBar::_notification(int p_what) {

	if (p_what==NOTIFICATION_DRAW) {

		RID ci = get_canvas_item();

		Ref<Texture> decr = hilite==HILITE_DECR ? get_icon("decrement_hilite") : get_icon("decrement");
		Ref<Texture> incr = hilite==HILITE_INCR ? get_icon("increment_hilite") : get_icon("increment");
		Ref<StyleBox> bg = has_focus() ? get_stylebox("scroll_focus") : get_stylebox("scroll");
		Ref<StyleBox> grabber = (drag.active || hilite==HILITE_RANGE) ? get_stylebox("grabber_hilite") : get_stylebox("grabber");

		Point2 ofs;

		VisualServer *vs = VisualServer::get_singleton();

		vs->canvas_item_add_texture_rect( ci, Rect2( Point2(), decr->get_size()),decr->get_rid() );

		if (orientation==HORIZONTAL)
			ofs.x+=decr->get_width();
		else
			ofs.y+=decr->get_height();

		Size2 area=get_size();

		if (orientation==HORIZONTAL)
			area.width-=incr->get_width()+decr->get_width();
		else
			area.height-=incr->get_height()+decr->get_height();

		bg->draw(ci,Rect2(ofs,area));

		if (orientation==HORIZONTAL)
			ofs.width+=area.width;
		else
			ofs.height+=area.height;

		vs->canvas_item_add_texture_rect( ci, Rect2( ofs, decr->get_size()),incr->get_rid() );
		Rect2 grabber_rect;

		if (orientation==HORIZONTAL) {

			grabber_rect.size.width=get_grabber_size();
			grabber_rect.size.height=get_size().height;
			grabber_rect.pos.y=0;
			grabber_rect.pos.x=get_grabber_offset()+decr->get_width()+bg->get_margin( MARGIN_LEFT );
		} else {

			grabber_rect.size.width=get_size().width;
			grabber_rect.size.height=get_grabber_size();
			grabber_rect.pos.y=get_grabber_offset()+decr->get_height()+bg->get_margin( MARGIN_TOP );
			grabber_rect.pos.x=0;
		}

		grabber->draw(ci,grabber_rect);

	}

	if (p_what==NOTIFICATION_ENTER_TREE) {


		if (has_node(drag_slave_path)) {
			Node *n = get_node(drag_slave_path);
			drag_slave=n->cast_to<Control>();
		}

		if (drag_slave) {
			drag_slave->connect("gui_input",this,"_drag_slave_input");
			drag_slave->connect("tree_exited",this,"_drag_slave_exit",varray(),CONNECT_ONESHOT);
		}


	}
	if (p_what==NOTIFICATION_EXIT_TREE) {

		if (drag_slave) {
			drag_slave->disconnect("gui_input",this,"_drag_slave_input");
			drag_slave->disconnect("tree_exited",this,"_drag_slave_exit");
		}

		drag_slave=NULL;

	}

	if (p_what==NOTIFICATION_FIXED_PROCESS) {

		if (drag_slave_touching)  {

			if (drag_slave_touching_deaccel) {

				Vector2 pos = Vector2(orientation==HORIZONTAL?get_value():0,orientation==VERTICAL?get_value():0);
				pos+=drag_slave_speed*get_fixed_process_delta_time();

				bool turnoff=false;

				if (orientation==HORIZONTAL) {

					if (pos.x<0) {
						pos.x=0;
						turnoff=true;
					}

					if (pos.x > (get_max()-get_page())) {
						pos.x=get_max()-get_page();
						turnoff=true;
					}

					set_value(pos.x);

					float sgn_x = drag_slave_speed.x<0? -1 : 1;
					float val_x = Math::abs(drag_slave_speed.x);
					val_x-=1000*get_fixed_process_delta_time();

					if (val_x<0) {
						turnoff=true;
					}

					drag_slave_speed.x=sgn_x*val_x;

				} else {


					if (pos.y<0) {
						pos.y=0;
						turnoff=true;
					}

					if (pos.y > (get_max()-get_page())) {
						pos.y=get_max()-get_page();
						turnoff=true;
					}

					set_value(pos.y);

					float sgn_y = drag_slave_speed.y<0? -1 : 1;
					float val_y = Math::abs(drag_slave_speed.y);
					val_y-=1000*get_fixed_process_delta_time();

					if (val_y<0) {
						turnoff=true;
					}
					drag_slave_speed.y=sgn_y*val_y;
				}


				if (turnoff) {
					set_fixed_process(false);
					drag_slave_touching=false;
					drag_slave_touching_deaccel=false;
				}


			} else {


				if (time_since_motion==0 || time_since_motion>0.1) {

					Vector2 diff = drag_slave_accum - last_drag_slave_accum;
					last_drag_slave_accum=drag_slave_accum;
					drag_slave_speed=diff/get_fixed_process_delta_time();
				}

				time_since_motion+=get_fixed_process_delta_time();
			}
		}


	}

	if (p_what==NOTIFICATION_MOUSE_EXIT) {

		hilite=HILITE_NONE;
		update();
	}
}

double ScrollBar::get_grabber_min_size() const {

	Ref<StyleBox> grabber=get_stylebox("grabber");
	Size2 gminsize=grabber->get_minimum_size()+grabber->get_center_size();
	return (orientation==VERTICAL)?gminsize.height:gminsize.width;
}

double ScrollBar::get_grabber_size() const {

	float range = get_max()-get_min();
	if (range<=0)
		return 0;

	float page = (get_page()>0)? get_page() : 0;
//	if (grabber_range < get_step())
//		grabber_range=get_step();

	double area_size=get_area_size();
	double grabber_size = page / range * area_size;
	return grabber_size+get_grabber_min_size();

}

double ScrollBar::get_area_size() const {

	if (orientation==VERTICAL) {

		double area=get_size().height;
		area-=get_stylebox("scroll")->get_minimum_size().height;
		area-=get_icon("increment")->get_height();
		area-=get_icon("decrement")->get_height();
		area-=get_grabber_min_size();
		return area;

	} else if (orientation==HORIZONTAL) {

		double area=get_size().width;
		area-=get_stylebox("scroll")->get_minimum_size().width;
		area-=get_icon("increment")->get_width();
		area-=get_icon("decrement")->get_width();
		area-=get_grabber_min_size();
		return area;
	} else {

		return 0;
	}

}

double ScrollBar::get_area_offset() const {

	double ofs=0;

	if (orientation==VERTICAL) {

		ofs+=get_stylebox("hscroll")->get_margin( MARGIN_TOP );
		ofs+=get_icon("decrement")->get_height();

	}

	if (orientation==HORIZONTAL) {

		ofs+=get_stylebox("hscroll")->get_margin( MARGIN_LEFT );
		ofs+=get_icon("decrement")->get_width();
	}

	return ofs;
}

double ScrollBar::get_click_pos(const Point2& p_pos) const {


	float pos=(orientation==VERTICAL)?p_pos.y:p_pos.x;
	pos-=get_area_offset();

	float area=get_area_size();
	if (area==0)
		return 0;
	else
		return pos/area;

}

double ScrollBar::get_grabber_offset() const {


	return (get_area_size()) * get_unit_value();

}



Size2 ScrollBar::get_minimum_size() const {

	Ref<Texture> incr = get_icon("increment");
	Ref<Texture> decr = get_icon("decrement");
	Ref<StyleBox> bg = get_stylebox("scroll");
	Size2 minsize;

	if (orientation==VERTICAL) {

		minsize.width=MAX(incr->get_size().width,(bg->get_minimum_size()+bg->get_center_size()).width);
		minsize.height+=incr->get_size().height;
		minsize.height+=decr->get_size().height;
		minsize.height+=bg->get_minimum_size().height;
		minsize.height+=get_grabber_min_size();
	}

	if (orientation==HORIZONTAL) {

		minsize.height=MAX(incr->get_size().height,(bg->get_center_size()+bg->get_minimum_size()).height);
		minsize.width+=incr->get_size().width;
		minsize.width+=decr->get_size().width;
		minsize.width+=bg->get_minimum_size().width;
		minsize.width+=get_grabber_min_size();
	}

	return minsize;

}

void ScrollBar::set_custom_step(float p_custom_step) {

	custom_step=p_custom_step;
}

float ScrollBar::get_custom_step() const {

	return custom_step;
}


void ScrollBar::_drag_slave_exit() {

	if (drag_slave) {
		drag_slave->disconnect("gui_input",this,"_drag_slave_input");
	}
	drag_slave=NULL;
}


void ScrollBar::_drag_slave_input(const InputEvent& p_input) {

	switch(p_input.type) {

		case InputEvent::MOUSE_BUTTON: {

			const InputEventMouseButton &mb=p_input.mouse_button;

			if (mb.button_index!=1)
				break;

			if (mb.pressed) {

				if (drag_slave_touching) {
					set_fixed_process(false);
					drag_slave_touching_deaccel=false;
					drag_slave_touching=false;
					drag_slave_speed=Vector2();
					drag_slave_accum=Vector2();
					last_drag_slave_accum=Vector2();
					drag_slave_from=Vector2();
				}

				if (true) {
					drag_slave_speed=Vector2();
					drag_slave_accum=Vector2();
					last_drag_slave_accum=Vector2();
					//drag_slave_from=Vector2(h_scroll->get_val(),v_scroll->get_val());
					drag_slave_from= Vector2(orientation==HORIZONTAL?get_value():0,orientation==VERTICAL?get_value():0);

					drag_slave_touching=OS::get_singleton()->has_touchscreen_ui_hint();
					drag_slave_touching_deaccel=false;
					time_since_motion=0;
					if (drag_slave_touching) {
						set_fixed_process(true);
						time_since_motion=0;

					}
				}

			} else {

				if (drag_slave_touching) {

					if (drag_slave_speed==Vector2()) {
						drag_slave_touching_deaccel=false;
						drag_slave_touching=false;
						set_fixed_process(false);
					} else {

						drag_slave_touching_deaccel=true;
					}
				}
			}
		} break;
		case InputEvent::MOUSE_MOTION: {

			const InputEventMouseMotion &mm=p_input.mouse_motion;

			if (drag_slave_touching && ! drag_slave_touching_deaccel) {

				Vector2 motion = Vector2(mm.relative_x,mm.relative_y);

				drag_slave_accum-=motion;
				Vector2 diff = drag_slave_from+drag_slave_accum;

				if (orientation==HORIZONTAL)
					set_value(diff.x);
				//else
				//	drag_slave_accum.x=0;
				if (orientation==VERTICAL)
					set_value(diff.y);
				//else
				//	drag_slave_accum.y=0;
				time_since_motion=0;
			}

		} break;
	}
}

void ScrollBar::set_drag_slave(const NodePath& p_path) {

	if (is_inside_tree()) {

		if (drag_slave) {
			drag_slave->disconnect("gui_input",this,"_drag_slave_input");
			drag_slave->disconnect("tree_exited",this,"_drag_slave_exit");
		}
	}

	drag_slave=NULL;
	drag_slave_path=p_path;

	if (is_inside_tree()) {

		if (has_node(p_path)) {
			Node *n = get_node(p_path);
			drag_slave=n->cast_to<Control>();
		}

		if (drag_slave) {
			drag_slave->connect("gui_input",this,"_drag_slave_input");
			drag_slave->connect("tree_exited",this,"_drag_slave_exit",varray(),CONNECT_ONESHOT);
		}
	}
}

NodePath ScrollBar::get_drag_slave() const{


	return drag_slave_path;
}



#if 0

void ScrollBar::mouse_button(const Point2& p_pos, int b.button_index,bool b.pressed,int p_modifier_mask) {

	// wheel!

	if (b.button_index==BUTTON_WHEEL_UP && b.pressed) {

		if (orientation==VERTICAL)
			set_val( get_val() - get_page() / 4.0 );
		else
			set_val( get_val() + get_page() / 4.0 );

	}
	if (b.button_index==BUTTON_WHEEL_DOWN && b.pressed) {

		if (orientation==HORIZONTAL)
			set_val( get_val() - get_page() / 4.0 );
		else
			set_val( get_val() + get_page() / 4.0  );
	}

	if (b.button_index!=BUTTON_LEFT)
		return;

	if (b.pressed) {

		int ofs = orientation==VERTICAL ? p_pos.y : p_pos.x ;
		int grabber_ofs = get_grabber_offset();
		int grabber_size = get_grabber_size();

		if ( ofs < grabber_ofs ) {

			set_val( get_val() - get_page() );

		} else if (ofs > grabber_ofs + grabber_size ) {

			set_val( get_val() + get_page() );

		} else {


			drag.active=true;
			drag.pos_at_click=get_click_pos(p_pos);
			drag.value_at_click=get_unit_value();
		}


	} else {

		drag.active=false;
	}

}
void ScrollBar::mouse_motion(const Point2& p_pos, const Point2& p_rel, int b.button_index_mask) {

	if (!drag.active)
		return;

	double value_ofs=drag.value_at_click+(get_click_pos(p_pos)-drag.pos_at_click);


	value_ofs=value_ofs*( get_max() - get_min() );
	if (value_ofs<get_min())
		value_ofs=get_min();
	if (value_ofs>(get_max()-get_page()))
		value_ofs=get_max()-get_page();
	if (get_val()==value_ofs)
		return; //dont bother if the value is the same

	set_val( value_ofs );

}

bool ScrollBar::key(unsigned long p_unicode, unsigned long p_scan_code,bool b.pressed,bool p_repeat,int p_modifier_mask) {

	if (!b.pressed)
		return false;

	switch (p_scan_code) {

	case KEY_LEFT: {

		if (orientation!=HORIZONTAL)
			return false;
		set_val( get_val() - get_step() );

	} break;
	case KEY_RIGHT: {

		if (orientation!=HORIZONTAL)
			return false;
		set_val( get_val() + get_step() );

	} break;
	case KEY_UP: {

		if (orientation!=VERTICAL)
			return false;

		set_val( get_val() - get_step() );


	} break;
	case KEY_DOWN: {

		if (orientation!=VERTICAL)
			return false;
		set_val( get_val() + get_step() );

	} break;
	case KEY_HOME: {

		set_val( get_min() );

	} break;
	case KEY_END: {

		set_val( get_max() );

	} break;

	default:
		return false;

	}

	return true;
}



#endif

void ScrollBar::_bind_methods() {

	ClassDB::bind_method(_MD("_gui_input"),&ScrollBar::_gui_input);
	ClassDB::bind_method(_MD("set_custom_step","step"),&ScrollBar::set_custom_step);
	ClassDB::bind_method(_MD("get_custom_step"),&ScrollBar::get_custom_step);
	ClassDB::bind_method(_MD("_drag_slave_input"),&ScrollBar::_drag_slave_input);
	ClassDB::bind_method(_MD("_drag_slave_exit"),&ScrollBar::_drag_slave_exit);

	ADD_PROPERTY( PropertyInfo(Variant::REAL,"custom_step",PROPERTY_HINT_RANGE,"-1,4096"), _SCS("set_custom_step"),_SCS("get_custom_step"));

}


ScrollBar::ScrollBar(Orientation p_orientation)
{


	orientation=p_orientation;
	hilite=HILITE_NONE;
	custom_step=-1;
	drag_slave=NULL;

	drag.active=false;

	drag_slave_speed=Vector2();
	drag_slave_touching=false;
	drag_slave_touching_deaccel=false;

	if (focus_by_default)
		set_focus_mode( FOCUS_ALL );
	set_step(0);

}



ScrollBar::~ScrollBar()
{
}