GUI Function Summary
The GUI function library provides detailed descriptions of all of the library routines that comprise the PDQ Screen's GUI Toolkit. These GUI library routines are defined and declared in … 
. This page contains a categorized list of the functions. In most browsers, if you click on the name of the function, a popup box containing its glossary definition will appear. You can of course find the complete definitions for all the functions listed in alphabetic order in the GUI glossary.
The GUI Toolkit contains object oriented functions for controlling all aspects of the LCD display and touchscreen: button event recognition, press, hold and release events, menu generation, displaying graphic images, plotting graphs, controlling font type size and color, generating textboxes, and controlling the LCD display's backlight and beeper.
The GUI Toolkit is organized as a collection of objects with defined methods and properties.
Interpreting glossary definitions
Each entry in the GUI glossary includes the following elements:
A declaration of the routine. If it is a constant or a macro that does not require any arguments, then the name of the routine is simply presented. If it is a function, or a macro that behaves like a function, then the declaration looks like an ANSI-C function prototype, such as:
void Emit(uchar c)
where void tells us that there is no return value, and uchar c tells us that there is a single input parameter that is an unsigned character.
Declarations are provided for both the C (denoted C:) and Forth (denoted 4th:) languages.
- A detailed definition of what the routine does.
- Examples of usage in the C and Forth languages.
Type abbreviations used in function declarations
Standard type specifiers such as char, int, long, and float are used in the glossary declarations. In addition, we use six convenient typedefs that are defined in the TYPES.h header file:
typedef unsigned char | uchar; |
typedef unsigned int | uint; |
typedef unsigned long | ulong; |
typedef unsigned long | xaddr; |
typedef int | wchar; |
typedef unsigned int | uwchar; |
The meanings of the first three typedefs are obvious; they are abbreviations for unsigned types. The xaddr typedef means extended address, and is used when a 32-bit address parameter is passed. The wchar and uwchar stand for wide-char and unsigned wide-char. These types must be used when passing char types to any libraries or kernel functions.
Categorized list of GUI Toolkit functions
The GUI glossary presents definitions of all of the functions, constants and macros that are defined and declared by the GUI Toolkit. For convenience in finding useful functions, they are organized into the following subject sorted tables:
Object types
These constants representing object types are passed to New_Object() to create new objects:
| BUTTON | DISPLAY_SCREEN | FONT | GRAPHIC |
| PALETTE | PLOT | SCREEN | TEXTBOX |
Pre-instantiated objects
The GUI Toolkit contains the following pre-instantiated objects for your use:
| GUI_BUZZER() | GUI_DISPLAY() | GUI_ERROR() | GUI_FONT() | GUI_PALETTE() |
| GUI_PEN() | GUI_PWM_DAC() | GUI_SCREEN() | GUI_TOOLKIT() | GUI_TOUCHSCREEN() |
GUI methods
| Add_Character | Add_Data | Buzz |
| Calibrate | Clear | Clear_Error |
| Copy_Screen | Delete_Character | Draw |
| Get_Property | Graphic_To_Image | Has_Screen_Changed |
| Initialize_GUI | Load | New_Object |
| Read_Error | Redraw | Refresh |
| Screen_Has_Changed | Screen_To_Image | Service_GUI_Events |
| Set_Property | Simulate_Touch | Simulated_Touch_To_Image |
| STRING_TO_TEXTBOX | String_To_Textbox | Textbox_To_String |
| Un_Load |
Debug method
Errors
The following constants represent errors that may be returned by GUI methods. They are returned by the method Read_Error().
| BIT_DEPTH_DOES_NOT_MATCH | BUFFER_SIZE_OUT_OF_RANGE |
| BUFFER_SIZE_TOO_SMALL | DATA_OUT_OF_RANGE |
| DISPLAY_INITIALIZATION_FAILURE | FLASH_NOT_PROGRAMMABLE |
| HEAP_FULL | HEIGHT_OUT_OF_RANGE |
| INVALID_BIT_DEPTH | INVALID_DISPLAY_TYPE |
| INVALID_FONT | INVALID_GRAPHIC |
| INVALID_IMAGE | INVALID_IMAGE_FORMAT |
| INVALID_OBJECT | INVALID_PALETTE |
| INVALID_PEN_SHAPE | INVALID_PEN_TYPE |
| INVALID_PLOT | INVALID_PROPERTY |
| INVALID_SCREEN | INVALID_TEXTBOX |
| NO_ERROR | PLOT_FULL |
| TEXTBOX_SIZE_OUT_OF_RANGE | TOUCHSCREEN_INITIALIZATION_FAILURE |
| WIDTH_OUT_OF_RANGE | X_OUT_OF_RANGE |
| Y_OUT_OF_RANGE |
Properties
GUI objects are modified by setting their properties. The following tables show the properties of each of the GUI objects as named constants. You can send a property to an object using the method Set_Property(), and read it using Get_Property().
GUI_TOOLKIT() properties
| AVAILABLE_HEAP_SPACE | COMMUNICATIONS_TIMEOUT |
| DEFAULT_FONT | DEFAULT_PALETTE |
| GUI_FALSE | GUI_TRUE |
| HORIZONTAL_SNAP_TO_GRID | SERVICE_EVENTS |
| VERTICAL_SNAP_TO_GRID |
GUI_DISPLAY() properties
| DISPLAY_TYPE | BACKLIGHT_ON | BIT_DEPTH |
| BLANK_DISPLAY | CONTRAST | DIM_DISPLAY |
| HEIGHT_IN_PIXELS | INVERT_DISPLAY | WIDTH_IN_PIXELS |
The following constants are used in conjunction with the DISPLAY_TYPE property:
| COLOR_STN | COLOR_TFT | MONO_STN |
Screen properties
These properties apply to the GUI's SCREEN and DISPLAY_SCREEN objects.
| HEIGHT_IN_PIXELS | IN_DISPLAY | NUM_OBJECTS |
| SCREEN_ADDRESS | SCREEN_BACKGROUND | SCREEN_UNCHANGED |
| VISIBLE | WIDTH_IN_PIXELS | XY_NOT_IN_BUTTON |
GUI_TOUCHSCREEN() properties
| CAL_COORDS | LAST_EVENT | RAW_COORDS |
The following touchscreen event constants may be read from the LAST_EVENT property:
| HELD_EVENT | NO_EVENT | PRESS_EVENT | RELEASE_EVENT |
GUI_PEN() properties
| DRAW_COLOR | LAST_COORDS | PEN_TYPE | SHAPE | TARGET_SCREEN |
The following pen constants are used in conjunction with the PEN_TYPE and SHAPE properties.
| LINE | POINT | SET | UNSET |
GUI_BUZZER() properties
GUI_PWM_DAC() properties
| DAC_COUNT_CH0 | DAC_COUNT_CH1 | DAC_COUNT_CH2 |
| DAC_COUNT_CH3 | PWM_DUTY_PERIOD_CH0 | PWM_DUTY_PERIOD_CH1 |
| PWM_DUTY_PERIOD_CH2 | PWM_DUTY_PERIOD_CH3 |
Graphic properties
Font properties
Textbox properties
| BORDER | FIRST_VISIBLE_LINE | FONT_COLOR |
| HEIGHT_IN_PIXELS | RENDER | STRING_LENGTH |
| STRING_LINES | TEXTBOX_BACKGROUND | TEXTBOX_FONT |
| TEXTBOX_ROWS | WIDTH_IN_PIXELS |
Button properties
| BEEP_ON_HOLD | BEEP_ON_PRESS | BEEP_ON_RELEASE |
| BLOCK_ON_HOLD | BLOCK_ON_PRESS | BLOCK_ON_RELEASE |
| BUTTON_REFRESH | BUTTON_TEXTBOX | DRAW_GRAPHIC |
| HEIGHT_IN_PIXELS | HELD_EVENT_PROCEDURE | PRESS_EVENT_PROCEDURE |
| PRESS_GRAPHIC | RELEASE_EVENT_PROCEDURE | RELEASE_GRAPHIC |
| WIDTH_IN_PIXELS |
Plot properties
Palette properties
Color constants
These constants may be used to set the background color of a screen or textbox, the pixel or line color of the GUI_PEN(), or the color of a font if the default color palette is used.
| BLACK | WHITE | ||
| DARK_GREY | LIGHT_GREY | ||
| MAGENTA | LIGHT_MAGENTA | ||
| BLUE | LIGHT_BLUE | ||
| CYAN | LIGHT_CYAN | ||
| GREEN | LIGHT_GREEN | ||
| BROWN | YELLOW | ||
| RED | LIGHT_RED |