mirror of
https://github.com/DCC-EX/CommandStation-EX.git
synced 2024-11-24 16:46:13 +01:00
220 lines
7.1 KiB
C++
220 lines
7.1 KiB
C++
/*
|
|
* © 2021, Chris Harlow, Neil McKechnie. All rights reserved.
|
|
*
|
|
* This file is part of CommandStation-EX
|
|
*
|
|
* This is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation, either version 3 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* It is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with CommandStation. If not, see <https://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
// CAUTION: the device dependent parts of this class are created in the .ini
|
|
// using LCD_Implementation.h
|
|
|
|
/* The strategy for drawing the screen is as follows.
|
|
* 1) There are up to eight rows of text to be displayed.
|
|
* 2) Blank rows of text are ignored.
|
|
* 3) If there are more non-blank rows than screen lines,
|
|
* then all of the rows are displayed, with the rest of the
|
|
* screen being blank.
|
|
* 4) If there are fewer non-blank rows than screen lines,
|
|
* then a scrolling strategy is adopted so that, on each screen
|
|
* refresh, a different subset of the rows is presented.
|
|
* 5) On each entry into loop2(), a single operation is sent to the
|
|
* screen; this may be a position command or a character for
|
|
* display. This spreads the onerous work of updating the screen
|
|
* and ensures that other loop() functions in the application are
|
|
* not held up significantly. The exception to this is when
|
|
* the loop2() function is called with force=true, where
|
|
* a screen update is executed to completion. This is normally
|
|
* only done during start-up.
|
|
* The scroll mode is selected by defining SCROLLMODE as 0, 1 or 2
|
|
* in the config.h.
|
|
* #define SCROLLMODE 0 is scroll continuous (fill screen if poss),
|
|
* #define SCROLLMODE 1 is by page (alternate between pages),
|
|
* #define SCROLLMODE 2 is by row (move up 1 row at a time).
|
|
|
|
*/
|
|
|
|
#include "Display.h"
|
|
|
|
// Constructor - allocates device driver.
|
|
Display::Display(DisplayDevice *deviceDriver) {
|
|
_deviceDriver = deviceDriver;
|
|
// Get device dimensions in characters (e.g. 16x2).
|
|
numScreenColumns = _deviceDriver->getNumCols();
|
|
numScreenRows = _deviceDriver->getNumRows();
|
|
for (uint8_t row = 0; row < MAX_CHARACTER_ROWS; row++)
|
|
rowBuffer[row][0] = '\0';
|
|
|
|
addDisplay(0); // Add this display as display number 0
|
|
};
|
|
|
|
void Display::begin() {
|
|
_deviceDriver->begin();
|
|
_deviceDriver->clearNative();
|
|
}
|
|
|
|
void Display::_clear() {
|
|
_deviceDriver->clearNative();
|
|
for (uint8_t row = 0; row < MAX_CHARACTER_ROWS; row++)
|
|
rowBuffer[row][0] = '\0';
|
|
}
|
|
|
|
void Display::_setRow(uint8_t line) {
|
|
hotRow = line;
|
|
hotCol = 0;
|
|
rowBuffer[hotRow][0] = '\0'; // Clear existing text
|
|
}
|
|
|
|
size_t Display::_write(uint8_t b) {
|
|
if (hotRow >= MAX_CHARACTER_ROWS || hotCol >= MAX_CHARACTER_COLS) return -1;
|
|
rowBuffer[hotRow][hotCol] = b;
|
|
hotCol++;
|
|
rowBuffer[hotRow][hotCol] = '\0';
|
|
return 1;
|
|
}
|
|
|
|
// Refresh screen completely (will block until complete). Used
|
|
// during start-up.
|
|
void Display::_refresh() {
|
|
loop2(true);
|
|
}
|
|
|
|
// On normal loop entries, loop will only make one output request on each
|
|
// entry, to avoid blocking while waiting for the I2C.
|
|
void Display::_displayLoop() {
|
|
// If output device is busy, don't do anything on this loop
|
|
// This avoids blocking while waiting for the device to complete.
|
|
if (!_deviceDriver->isBusy()) loop2(false);
|
|
}
|
|
|
|
Display *Display::loop2(bool force) {
|
|
unsigned long currentMillis = millis();
|
|
|
|
if (!force) {
|
|
// See if we're in the time between updates
|
|
if ((currentMillis - lastScrollTime) < DISPLAY_SCROLL_TIME)
|
|
return NULL;
|
|
} else {
|
|
// force full screen update from the beginning.
|
|
rowFirst = 0;
|
|
rowCurrent = 0;
|
|
bufferPointer = 0;
|
|
noMoreRowsToDisplay = false;
|
|
slot = 0;
|
|
}
|
|
|
|
do {
|
|
if (bufferPointer == 0) {
|
|
// Search for non-blank row
|
|
while (!noMoreRowsToDisplay) {
|
|
if (!isCurrentRowBlank()) break;
|
|
moveToNextRow();
|
|
if (rowCurrent == rowFirst) noMoreRowsToDisplay = true;
|
|
}
|
|
|
|
if (noMoreRowsToDisplay) {
|
|
// No non-blank lines left, so draw blank line
|
|
buffer[0] = '\0';
|
|
} else {
|
|
// Non-blank line found, so copy it (including terminator)
|
|
for (uint8_t i = 0; i <= MAX_CHARACTER_COLS; i++)
|
|
buffer[i] = rowBuffer[rowCurrent][i];
|
|
}
|
|
_deviceDriver->setRowNative(slot); // Set position for display
|
|
charIndex = 0;
|
|
bufferPointer = &buffer[0];
|
|
} else {
|
|
// Write next character, or a space to erase current position.
|
|
char ch = *bufferPointer;
|
|
if (ch) {
|
|
_deviceDriver->writeNative(ch);
|
|
bufferPointer++;
|
|
} else {
|
|
_deviceDriver->writeNative(' ');
|
|
}
|
|
|
|
if (++charIndex >= MAX_CHARACTER_COLS) {
|
|
// Screen slot completed, move to next nonblank row
|
|
bufferPointer = 0;
|
|
for (;;) {
|
|
moveToNextRow();
|
|
if (rowCurrent == rowFirst) {
|
|
noMoreRowsToDisplay = true;
|
|
break;
|
|
}
|
|
if (!isCurrentRowBlank()) break;
|
|
}
|
|
// Move to next screen slot, if available
|
|
slot++;
|
|
if (slot >= numScreenRows) {
|
|
// Last slot on screen written, so get ready for next screen update.
|
|
#if SCROLLMODE==0
|
|
// Scrollmode 0 scrolls continuously. If the rows fit on the screen,
|
|
// then restart at row 0, but otherwise continue with the row
|
|
// after the last one displayed.
|
|
if (countNonBlankRows() <= numScreenRows)
|
|
rowCurrent = 0;
|
|
rowFirst = rowCurrent;
|
|
#elif SCROLLMODE==1
|
|
// Scrollmode 1 scrolls by page, so if the last page has just completed then
|
|
// next time restart with row 0.
|
|
if (noMoreRowsToDisplay)
|
|
rowFirst = rowCurrent = 0;
|
|
#else
|
|
// Scrollmode 2 scrolls by row. If the rows don't fit on the screen,
|
|
// then start one row further on next time. If they do fit, then
|
|
// show them in order and start next page at row 0.
|
|
if (countNonBlankRows() <= numScreenRows) {
|
|
rowFirst = rowCurrent = 0;
|
|
} else {
|
|
// Find first non-blank row after the previous first row
|
|
rowCurrent = rowFirst;
|
|
do {
|
|
moveToNextRow();
|
|
} while (isCurrentRowBlank());
|
|
rowFirst = rowCurrent;
|
|
}
|
|
#endif
|
|
noMoreRowsToDisplay = false;
|
|
slot = 0;
|
|
lastScrollTime = currentMillis;
|
|
return NULL;
|
|
}
|
|
}
|
|
}
|
|
} while (force);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
bool Display::isCurrentRowBlank() {
|
|
return (rowBuffer[rowCurrent][0] == '\0');
|
|
}
|
|
|
|
void Display::moveToNextRow() {
|
|
// Skip blank rows
|
|
if (++rowCurrent >= MAX_CHARACTER_ROWS)
|
|
rowCurrent = 0;
|
|
}
|
|
|
|
uint8_t Display::countNonBlankRows() {
|
|
uint8_t count = 0;
|
|
for (uint8_t rowNumber=0; rowNumber<MAX_CHARACTER_ROWS; rowNumber++) {
|
|
if (rowBuffer[rowNumber][0] != '\0')
|
|
count++;
|
|
}
|
|
return count;
|
|
}
|
|
|