tesseract/viewer/svpaint.cpp
2014-04-28 23:10:48 +00:00

227 lines
8.4 KiB
C++

// Copyright 2007 Google Inc. All Rights Reserved.
//
// Author: Joern Wanke
//
// Simple drawing program to illustrate ScrollView capabilities.
//
// Functionality:
// - The menubar is used to select from different sample styles of input.
// - With the RMB it is possible to change the RGB values in different
// popup menus.
// - A LMB click either draws point-to-point, point or text.
// - A LMB dragging either draws a line, a rectangle or ellipse.
// Include automatically generated configuration file if running autoconf.
#ifdef HAVE_CONFIG_H
#include "config_auto.h"
#endif
#ifndef GRAPHICS_DISABLED
#include "scrollview.h"
#include "svmnode.h"
#include <stdlib.h>
#include <iostream>
// The current color values we use, initially white (== ScrollView::WHITE).
int rgb[3] = { 255, 255, 255 };
class SVPaint : public SVEventHandler {
public:
explicit SVPaint(const char* server_name);
// This is the main event handling function that we need to overwrite, defined
// in SVEventHandler.
void Notify(const SVEvent* sv_event);
private:
// The Handler take care of the SVET_POPUP, SVET_MENU, SVET_CLICK and
// SVET_SELECTION events.
void PopupHandler(const SVEvent* sv_event);
void MenuBarHandler(const SVEvent* sv_event);
void ClickHandler(const SVEvent* sv_event);
void SelectionHandler(const SVEvent* sv_event);
// Convenience functions to build little menus.
SVMenuNode* BuildPopupMenu();
SVMenuNode* BuildMenuBar();
// Our window.
ScrollView* window_;
// The mode we are in when an SVET_CLICK or an SVET_SELECTION event occurs.
int click_mode_;
int drag_mode_;
// In the point-to-point drawing mode, we need to set a start-point the first
// time we call it (e.g. call SetCursor).
bool has_start_point_;
};
// Build a sample popup menu.
SVMenuNode* SVPaint::BuildPopupMenu() {
SVMenuNode* root = new SVMenuNode(); // Empty root node
// Initial color is white, so we all values to 255.
root->AddChild("R", // Shown caption.
1, // assoc. command_id.
"255", // initial value.
"Red Color Value?"); // Shown description.
root->AddChild("G", 2, "255", "Green Color Value?");
root->AddChild("B", 3, "255", "Blue Color Value?");
return root;
}
// Build a sample menu bar.
SVMenuNode* SVPaint::BuildMenuBar() {
SVMenuNode* root = new SVMenuNode(); // Empty root node
// Create some submenus and add them to the root.
SVMenuNode* click = root->AddChild("Clicking");
SVMenuNode* drag = root->AddChild("Dragging");
// Put some nodes into the submenus.
click->AddChild("Point to Point Drawing", // Caption.
1); // command_id.
click->AddChild("Point Drawing", 2);
click->AddChild("Text Drawing", 3);
drag->AddChild("Line Drawing", 4);
drag->AddChild("Rectangle Drawing", 5);
drag->AddChild("Ellipse Drawing", 6);
return root;
}
// Takes care of the SVET_POPUP events.
// In our case, SVET_POPUP is used to set RGB values.
void SVPaint::PopupHandler(const SVEvent* sv_event) {
// Since we only have the RGB values as popup items,
// we take a shortcut to not bloat up code:
rgb[sv_event->command_id - 1] = atoi(sv_event->parameter);
window_->Pen(rgb[0], rgb[1], rgb[2]);
}
// Takes care of the SVET_MENU events.
// In our case, we change either the click_mode_ (commands 1-3)
// or the drag_mode_ (commands 4-6).
void SVPaint::MenuBarHandler(const SVEvent* sv_event) {
if ((sv_event->command_id > 0) && (sv_event->command_id < 4)) {
click_mode_ = sv_event->command_id;
has_start_point_ = false;
} else { drag_mode_ = sv_event->command_id; }
}
// Takes care of the SVET_CLICK events.
// Depending on the click_mode_ we are in, either do Point-to-Point drawing,
// point drawing, or draw text.
void SVPaint::ClickHandler(const SVEvent* sv_event) {
switch (click_mode_) {
case 1: //Point to Point
if (has_start_point_) { window_->DrawTo(sv_event->x, sv_event->y);
} else {
has_start_point_ = true;
window_->SetCursor(sv_event->x, sv_event->y);
}
break;
case 2: //Point Drawing..simulated by drawing a 1 pixel line.
window_->Line(sv_event->x, sv_event->y, sv_event->x, sv_event->y);
break;
case 3: //Text
// We show a modal input dialog on our window, then draw the input and
// finally delete the input pointer.
char* p = window_->ShowInputDialog("Text:");
window_->Text(sv_event->x, sv_event->y, p);
delete [] p;
break;
}
}
// Takes care of the SVET_SELECTION events.
// Depending on the drag_mode_ we are in, either draw a line, a rectangle or
// an ellipse.
void SVPaint::SelectionHandler(const SVEvent* sv_event) {
switch (drag_mode_) {
//FIXME inversed x_size, y_size
case 4: //Line
window_->Line(sv_event->x, sv_event->y,
sv_event->x - sv_event->x_size,
sv_event->y - sv_event->y_size);
break;
case 5: //Rectangle
window_->Rectangle(sv_event->x, sv_event->y,
sv_event->x - sv_event->x_size,
sv_event->y - sv_event->y_size);
break;
case 6: //Ellipse
window_->Ellipse(sv_event->x - sv_event->x_size,
sv_event->y - sv_event->y_size,
sv_event->x_size, sv_event->y_size);
break;
}
}
// The event handling function from ScrollView which we have to overwrite.
// We handle CLICK, SELECTION, MENU and POPUP and throw away all other events.
void SVPaint::Notify(const SVEvent* sv_event) {
if (sv_event->type == SVET_CLICK) { ClickHandler(sv_event); }
else if (sv_event->type == SVET_SELECTION) { SelectionHandler(sv_event); }
else if (sv_event->type == SVET_MENU) { MenuBarHandler(sv_event); }
else if (sv_event->type == SVET_POPUP) { PopupHandler(sv_event); }
else {} //throw other events away
}
// Builds a new window, initializes the variables and event handler and builds
// the menu.
SVPaint::SVPaint(const char *server_name) {
window_ = new ScrollView("ScrollView Paint Example", // window caption
0, 0, // x,y window position
500, 500, // window size
500, 500, // canvas size
false, // whether the Y axis is inversed.
// this is included due to legacy
// reasons for tesseract and enables
// us to have (0,0) as the LOWER left
// of the coordinate system.
server_name); // the server address.
// Set the start modes to point-to-point and line drawing.
click_mode_ = 1;
drag_mode_ = 4;
has_start_point_ = false;
// Bild our menus and add them to the window. The flag illustrates whether
// this is a menu bar.
SVMenuNode* popup_menu = BuildPopupMenu();
popup_menu->BuildMenu(window_,false);
SVMenuNode* bar_menu = BuildMenuBar();
bar_menu->BuildMenu(window_,true);
// Set the initial color values to White (could also be done by
// passing (rgb[0], rgb[1], rgb[2]).
window_->Pen(ScrollView::WHITE);
window_->Brush(ScrollView::WHITE);
// Adds the event handler to the window. This actually ensures that Notify
// gets called when events occur.
window_->AddEventHandler(this);
// Set the window visible (calling this is important to actually render
// everything. Without this call, the window would also be drawn, but the
// menu bars would be missing.
window_->SetVisible(true);
// Rest this thread until its window is destroyed.
// Note that a special eventhandling thread was created when constructing
// the window. Due to this, the application will not deadlock here.
window_->AwaitEvent(SVET_DESTROY);
// We now have 3 Threads running:
// (1) The MessageReceiver thread which fetches messages and distributes them
// (2) The EventHandler thread which handles all events for window_
// (3) The main thread which waits on window_ for a DESTROY event (blocked)
}
// If a parameter is given, we try to connect to the given server.
// This enables us to test the remote capabilites of ScrollView.
int main(int argc, char** argv) {
const char* server_name;
if (argc > 1) { server_name = argv[1]; } else { server_name = "localhost"; }
SVPaint svp(server_name);
}
#endif // GRAPHICS_DISABLED