1
0
mirror of https://github.com/DCC-EX/CommandStation-EX.git synced 2024-12-23 04:41:24 +01:00

Refactor Display handler to (hopefully) improve clarity.

This commit is contained in:
Neil McKechnie 2023-02-22 21:06:03 +00:00
parent c2e8557c4c
commit 4eb277f19e
2 changed files with 63 additions and 58 deletions

View File

@ -36,7 +36,7 @@
* 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.
* only noMoreRowsToDisplay 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),
@ -53,9 +53,9 @@ Display::Display(DisplayDevice *deviceDriver) {
// Get device dimensions in characters (e.g. 16x2).
numCharacterColumns = _deviceDriver->getNumCols();
numCharacterRows = _deviceDriver->getNumRows();;
for (uint8_t row=0; row<MAX_CHARACTER_ROWS; row++)
rowBuffer[row] = (char *)calloc(1, MAX_CHARACTER_COLS+1);
topRow = -1; // loop2 will fill from row 0
for (uint8_t row = 0; row < MAX_CHARACTER_ROWS; row++)
rowBuffer[row][0] = '\0';
topRow = ROW_INITIAL; // loop2 will fill from row 0
addDisplay(0); // Add this display as display number 0
};
@ -69,13 +69,13 @@ void Display::_clear() {
_deviceDriver->clearNative();
for (uint8_t row = 0; row < MAX_CHARACTER_ROWS; row++)
rowBuffer[row][0] = '\0';
topRow = -1; // loop2 will fill from row 0
topRow = ROW_INITIAL; // loop2 will fill from row 0
}
void Display::_setRow(uint8_t line) {
hotRow = line;
hotCol = 0;
rowBuffer[hotRow][hotCol] = 0; // Clear existing text
rowBuffer[hotRow][0] = 0; // Clear existing text
}
size_t Display::_write(uint8_t b) {
@ -109,63 +109,57 @@ Display *Display::loop2(bool force) {
return NULL;
} else {
// force full screen update from the beginning.
rowFirst = -1;
rowNext = 0;
rowFirst = ROW_INITIAL;
rowNext = ROW_INITIAL;
bufferPointer = 0;
done = false;
noMoreRowsToDisplay = false;
slot = 0;
}
do {
if (bufferPointer == 0) {
// Find a line of data to write to the screen.
if (rowFirst < 0) rowFirst = rowNext;
skipBlankRows();
if (!done) {
// Non-blank line found, so copy it.
for (uint8_t i = 0; i < sizeof(buffer); i++)
if (rowFirst == ROW_INITIAL) rowFirst = rowNext;
if (findNextNonBlankRow()) {
// Non-blank line found, so copy it (including terminator)
for (uint8_t i = 0; i <= MAX_CHARACTER_COLS; i++)
buffer[i] = rowBuffer[rowNext][i];
} else
buffer[0] = '\0'; // Empty line
} else {
// No non-blank lines left, so draw a blank line
buffer[0] = 0;
}
_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
} else {
_deviceDriver->writeNative(' ');
}
if (++charIndex >= MAX_CHARACTER_COLS) {
// Screen slot completed, move to next slot on screen
slot++;
bufferPointer = 0;
if (!done) {
moveToNextRow();
skipBlankRows();
}
}
if (slot >= numCharacterRows) {
// Last slot finished, reset ready for next screen update.
slot++;
if (slot >= numCharacterRows) {
// Last slot on screen written, reset ready for next screen update.
#if SCROLLMODE==2
if (!done) {
// On next refresh, restart one row on from previous start.
rowNext = rowFirst;
moveToNextRow();
skipBlankRows();
}
if (!noMoreRowsToDisplay) {
// On next refresh, restart one row on from previous start.
rowNext = rowFirst;
findNextNonBlankRow();
}
#endif
done = false;
slot = 0;
rowFirst = -1;
lastScrollTime = currentMillis;
return NULL;
noMoreRowsToDisplay = false;
slot = 0;
rowFirst = ROW_INITIAL;
lastScrollTime = currentMillis;
return NULL;
}
}
}
} while (force);
@ -173,19 +167,30 @@ Display *Display::loop2(bool force) {
return NULL;
}
void Display::moveToNextRow() {
rowNext = rowNext + 1;
if (rowNext >= MAX_CHARACTER_ROWS) rowNext = 0;
bool Display::findNextNonBlankRow() {
while (!noMoreRowsToDisplay) {
if (rowNext == ROW_INITIAL)
rowNext = 0;
else
rowNext = rowNext + 1;
if (rowNext >= MAX_CHARACTER_ROWS) rowNext = ROW_INITIAL;
#if SCROLLMODE == 1
// Finished if we've looped back to row 0
if (rowNext == 0) done = true;
// Finished if we've looped back to start
if (rowNext == ROW_INITIAL) {
noMoreRowsToDisplay = true;
return false;
}
#else
// Finished if we're back to the first one shown
if (rowNext == rowFirst) done = true;
// Finished if we're back to the first one shown
if (rowNext == rowFirst) {
noMoreRowsToDisplay = true;
return false;
}
#endif
}
void Display::skipBlankRows() {
while (!done && rowBuffer[rowNext][0] == 0)
moveToNextRow();
if (rowBuffer[rowNext][0] != 0) {
// Found non-blank row
return true;
}
}
return false;
}

View File

@ -40,6 +40,7 @@ public:
static const int MAX_CHARACTER_ROWS = 8;
static const int MAX_CHARACTER_COLS = MAX_MSG_SIZE;
static const long DISPLAY_SCROLL_TIME = 3000; // 3 seconds
static const uint8_t ROW_INITIAL = 255;
private:
DisplayDevice *_deviceDriver;
@ -47,18 +48,18 @@ private:
unsigned long lastScrollTime = 0;
uint8_t hotRow = 0;
uint8_t hotCol = 0;
int8_t topRow = 0;
uint8_t topRow = 0;
uint8_t slot = 0;
int8_t rowFirst = -1;
int8_t rowNext = 0;
uint8_t rowFirst = ROW_INITIAL;
uint8_t rowNext = ROW_INITIAL;
uint8_t charIndex = 0;
char buffer[MAX_CHARACTER_COLS + 1];
char* bufferPointer = 0;
bool done = false;
bool noMoreRowsToDisplay = false;
uint16_t numCharacterRows;
uint16_t numCharacterColumns = MAX_CHARACTER_COLS;
char *rowBuffer[MAX_CHARACTER_ROWS];
char rowBuffer[MAX_CHARACTER_ROWS][MAX_CHARACTER_COLS+1];
public:
void begin() override;
@ -68,8 +69,7 @@ public:
void _refresh() override;
void _displayLoop() override;
Display *loop2(bool force);
void moveToNextRow();
void skipBlankRows();
bool findNextNonBlankRow();
};