The SimpleCxxLib package

#include "gwindow.h"

class GWindow

This class represents a graphics window that supports simple graphics. Each GWindow consists of two layers. The background layer provides a surface for drawing static pictures that involve no animation. Graphical objects drawn in the background layer are persistent and do not require the client to update the contents of the window. The foreground layer contains graphical objects that are redrawn as necessary.

The GWindow class includes several methods that draw lines, rectangles, and ovals on the background layer without making use of the facilities of the gobjects.h interface. For example, the following program draws a diamond, rectangle, and oval at the center of the window. 

   int main() {
      GWindow gw;
      cout << "This program draws a diamond, rectangle, and oval." << endl;
      double width = gw.getWidth();
      double height = gw.getHeight();
      gw.drawLine(0, height / 2, width / 2, 0);
      gw.drawLine(width / 2, 0, width, height / 2);
      gw.drawLine(width, height / 2, width / 2, height);
      gw.drawLine(width / 2, height, 0, height / 2);
      gw.setColor("BLUE");
      gw.fillRect(width / 4, height / 4, width / 2, height / 2);
      gw.setColor("GRAY");
      gw.fillOval(width / 4, height / 4, width / 2, height / 2);
      return 0;
   }
A GWindow object may be freely copied, after which all copies refer to the same window.
Constructor
GWindow()
GWindow(width, height) 		Creates a window, either of the specified size or a default size.
Methods
add(gobj)
add(gobj, x, y) 		Adds the GObject to the foreground layer of the window.
addToRegion(interactor, region) Adds the interactor (which can also be a GLabel) to the control strip specified by the region parameter.
clear() Clears the contents of the window.
close() Deletes the window from the screen.
draw(gobj)
draw(gobj, x, y) 		Draws the GObject on the background layer.
drawLine(p0, p1)
drawLine(x0, y0, x1, y1) 		Draws a line connecting the specified points.
drawOval(bounds)
drawOval(x, y, width, height) 		Draws the frame of a oval with the specified bounds.
drawPolarLine(p0, r, theta)
drawPolarLine(x0, y0, r, theta) 		Draws a line of length r in the direction theta from the initial point.
drawRect(bounds)
drawRect(x, y, width, height) 		Draws the frame of a rectangle with the specified bounds.
fillOval(bounds)
fillOval(x, y, width, height) 		Fills the frame of a oval with the specified bounds.
fillRect(bounds)
fillRect(x, y, width, height) 		Fills the frame of a rectangle with the specified bounds.
getColor() Returns the current color as a string in the form "#rrggbb".
getGObjectAt(x, y) Returns a pointer to the topmost GObject containing the point (x, y), or NULL if no such object exists.
getHeight() Returns the height of the graphics window in pixels.
getWidth() Returns the width of the graphics window in pixels.
getWindowTitle() Returns the title of the graphics window.
isVisible() Tests whether the window is visible.
remove(gobj) Removes the object from the window.
removeFromRegion(interactor, region) Adds the interactor (which can also be a GLabel) to the control strip specified by the region parameter.
repaint() Schedule a repaint on this window.
requestFocus() Asks the system to assign the keyboard focus to the window, which brings it to the top and ensures that key events are delivered to the window.
setColor(color) Sets the color used for drawing.
setRegionAlignment(region, align) Sets the alignment of the specified side region as specified by the string align.
setVisible(flag) Determines whether the window is visible on the screen.
setWindowTitle(title) Sets the title of the graphics window.
Operators
if (w1 != w2) ... Checks whether the two objects refer to different windows.
if (w1 == w2) ... Checks whether the two objects refer to the same window.
Functions
convertColorToRGB(colorName) Converts a color name into an integer that encodes the red, green, and blue components of the color.
convertRGBToColor(rgb) Converts an rgb value into a color name in the form "#rrggbb".
exitGraphics() Closes all graphics windows and exits from the application without waiting for any additional user interaction.
getScreenHeight() Returns the height of the entire display screen.
getScreenWidth() Returns the width of the entire display screen.
pause(milliseconds) Pauses for the indicated number of milliseconds.
repaint() Issues a request to update all graphics windows.
waitForClick() Waits for a mouse click to occur anywhere in any window.

Constructor detail

GWindow();
GWindow(double width, double height);
Creates a window, either of the specified size or a default size.

Usage:

GWindow gw;
GWindow gw(width, height);

Method detail

void close();
Deletes the window from the screen.

Usage:

gw.close();

void requestFocus();
Asks the system to assign the keyboard focus to the window, which brings it to the top and ensures that key events are delivered to the window. Clicking in the window automatically requests the focus.

Usage:

gw.requestFocus();

void clear();
Clears the contents of the window.

Usage:

gw.clear();

void setVisible(bool flag);
Determines whether the window is visible on the screen.

Usage:

gw.setVisible(flag);

bool isVisible();
Tests whether the window is visible.

Usage:

if (gw.isVisible()) ...

void drawLine(const GPoint & p0, const GPoint & p1);
void drawLine(double x0, double y0, double x1, double y1);
Draws a line connecting the specified points.

Usage:

gw.drawLine(p0, p1);
gw.drawLine(x0, y0, x1, y1);

GPoint drawPolarLine(const GPoint & p0, double r, double theta);
GPoint drawPolarLine(double x0, double y0, double r, double theta);
Draws a line of length r in the direction theta from the initial point. The angle theta is measured in degrees counterclockwise from the +x axis. The method returns the end point of the line.

Usage:

GPoint p1 = gw.drawPolarLine(p0, r, theta);
GPoint p1 = gw.drawPolarLine(x0, y0, r, theta);

void drawOval(const GRectangle & bounds);
void drawOval(double x, double y, double width, double height);
Draws the frame of a oval with the specified bounds.

Usage:

gw.drawOval(bounds);
gw.drawOval(x, y, width, height);

void fillOval(const GRectangle & bounds);
void fillOval(double x, double y, double width, double height);
Fills the frame of a oval with the specified bounds.

Usage:

gw.fillOval(bounds);
gw.fillOval(x, y, width, height);

void drawRect(const GRectangle & bounds);
void drawRect(double x, double y, double width, double height);
Draws the frame of a rectangle with the specified bounds.

Usage:

gw.drawRect(bounds);
gw.drawRect(x, y, width, height);

void fillRect(const GRectangle & bounds);
void fillRect(double x, double y, double width, double height);
Fills the frame of a rectangle with the specified bounds.

Usage:

gw.fillRect(bounds);
gw.fillRect(x, y, width, height);

void setColor(string color);
void setColor(int color);
Sets the color used for drawing. The color parameter is usually one of the predefined color names: BLACK, BLUE, CYAN, DARK_GRAY, GRAY, GREEN, LIGHT_GRAY, MAGENTA, ORANGE, PINK, RED, WHITE, and YELLOW. The case of the individual letters in the color name is ignored, as are spaces and underscores, so that the color DARK_GRAY can be written as "Dark Gray".

The color can also be specified as a string in the form "#rrggbb" where rr, gg, and bb are pairs of hexadecimal digits indicating the red, green, and blue components of the color.

Usage:

gw.setColor(color);

string getColor();
Returns the current color as a string in the form "#rrggbb". In this string, the values rr, gg, and bb are two-digit hexadecimal values representing the red, green, and blue components of the color, respectively.

Usage:

string color = gw.getColor();

double getWidth();
Returns the width of the graphics window in pixels.

Usage:

double width = gw.getWidth();

double getHeight();
Returns the height of the graphics window in pixels.

Usage:

double height = gw.getHeight();

void repaint();
Schedule a repaint on this window.

Usage:

gw.repaint();

void setWindowTitle(string title);
Sets the title of the graphics window.

Usage:

gw.setWindowTitle(title);

string getWindowTitle();
Returns the title of the graphics window.

Usage:

string title = gw.getWindowTitle();

void draw(const GObject & gobj);
void draw(GObject *gobj);
void draw(const GObject *gobj);
void draw(GObject & gobj, double x, double y);
void draw(GObject *gobj, double x, double y);
Draws the GObject on the background layer. For convenience, the gobj parameter may be passed either as a constant reference or as a pointer. If the x and y parameters are included, the object is moved to that location before drawing.

Usage:

gw.draw(gobj);
gw.draw(gobj, x, y);

void add(GObject *gobj);
void add(GObject *gobj, double x, double y);
Adds the GObject to the foreground layer of the window. The second form of the call sets the location of the object to (x, y) first.

In terms of memory management, adding a GObject pointer to a GWindow transfers control of that object from the client to the window manager. Deleting a GWindow automatically deletes any GObjects it contains.

Usage:

gw.add(gobj);
gw.add(gobj, x, y);

void remove(GObject *gobj);
Removes the object from the window.

Usage:

gw.remove(gobj);

void addToRegion(GInteractor *gobj, string region);
void addToRegion(GLabel *gobj, string region);
Adds the interactor (which can also be a GLabel) to the control strip specified by the region parameter. The region parameter must be one of the strings "NORTH", "EAST", "SOUTH", or "WEST".

Usage:

gw.addToRegion(interactor, region);

void removeFromRegion(GInteractor *gobj, string region);
void removeFromRegion(GLabel *gobj, string region);
Adds the interactor (which can also be a GLabel) to the control strip specified by the region parameter. The region parameter must be one of the strings "NORTH", "EAST", "SOUTH", or "WEST".

Usage:

gw.removeFromRegion(interactor, region);

GObject *getGObjectAt(double x, double y);
Returns a pointer to the topmost GObject containing the point (x, y), or NULL if no such object exists.

Usage:

GObject *gobj = getGObjectAt(x, y);

void setRegionAlignment(string region, string align);
Sets the alignment of the specified side region as specified by the string align. The region parameter must be one of the strings "NORTH", "EAST", "SOUTH", or "WEST" and the align parameter must be "LEFT", "RIGHT", or "CENTER". By default, side panels use CENTER alignment.

Usage:

gw.setRegionAlignment(region, align);

Operator detail

bool operator==(GWindow w2);
Checks whether the two objects refer to the same window.

Usage:

if (w1 == w2) ...

bool operator!=(GWindow w2);
Checks whether the two objects refer to different windows.

Usage:

if (w1 != w2) ...

Function detail

void repaint();
Issues a request to update all graphics windows. This function is called automatically when the program pauses, waits for an event, waits for user input on the console, or terminates. As a result, most clients never need to call repaint explicitly.

Usage:

repaint();

void pause(double milliseconds);
Pauses for the indicated number of milliseconds. This function is useful for animation where the motion would otherwise be too fast.

Usage:

pause(milliseconds);

double getScreenWidth();
Returns the width of the entire display screen.

Usage:

width = getScreenWidth();

double getScreenHeight();
Returns the height of the entire display screen.

Usage:

height = getScreenHeight();

int convertColorToRGB(string colorName);
Converts a color name into an integer that encodes the red, green, and blue components of the color.

Usage:

int rgb = convertColorToRGB(colorName);

string convertRGBToColor(int rgb);
Converts an rgb value into a color name in the form "#rrggbb". Each of the rr, gg, and bb values are two-digit hexadecimal numbers indicating the intensity of that component.

Usage:

int colorName = convertRGBToColor(rgb);

void waitForClick();
Waits for a mouse click to occur anywhere in any window.

Usage:

waitForClick();

void exitGraphics();
Closes all graphics windows and exits from the application without waiting for any additional user interaction.

Usage:

exitGraphics();