Prior to multi-screen

SSD1306/writer.py

@@ -37,6 +37,7 @@ class Writer():
     text_col = 0
     row_clip = False  # Clip or scroll when screen full
     col_clip = False  # Clip or new line when row is full
+    wrap = True  # Word wrap
 
     @classmethod
     def set_textpos(cls, row=None, col=None):
@@ -47,12 +48,14 @@ class Writer():
         return  Writer.text_row,  Writer.text_col
 
     @classmethod
-    def set_clip(cls, row_clip=None, col_clip=None):
+    def set_clip(cls, row_clip=None, col_clip=None, wrap=None):
         if row_clip is not None:
             Writer.row_clip = row_clip
         if col_clip is not None:
             Writer.col_clip = col_clip
-        return Writer.row_clip, Writer.col_clip
+        if wrap is not None:
+            Writer.wrap = wrap
+        return Writer.row_clip, Writer.col_clip, Writer.wrap
 
     def __init__(self, device, font, verbose=True):
         self.device = device
@@ -100,8 +103,23 @@ class Writer():
 
     def printstring(self, string, invert=False):
         #print('Writer.text_row = ', Writer.text_row)
+        # word wrapping. Assumes words separated by single space.
+        rstr = None
+        if Writer.wrap and self.stringlen(string) > self.screenwidth:
+            pos = 0
+            lstr = string[:]
+            while self.stringlen(lstr) > self.screenwidth:
+                pos = lstr.rfind(' ')
+                lstr = lstr[:pos]
+            if pos > 0:
+                rstr = string[pos + 1:]
+                string = lstr
+                
         for char in string:
             self._printchar(char, invert)
+        if rstr is not None:
+            self._printchar('\n')
+            self.printstring(rstr, invert)  # Recurse
 
     def stringlen(self, string):
         l = 0
@@ -172,14 +190,41 @@ class CWriter(Writer):
     def __init__(self,device, font, verbose=True):
         super().__init__(device, font, verbose)
         self.fgcolor = 1
+        self.cpos = 0
+        self.tab = 4
 
-    def setcolor(fgcolor, bgcolor):
+    def setcolor(self, fgcolor=None, bgcolor=None):
-        self.fgcolor = fgcolor
+        if fgcolor is not None:
-        self.bgcolor = bgcolor
+            self.fgcolor = fgcolor
+        if bgcolor is not None:
+            self.bgcolor = bgcolor
+        return self.fgcolor, self.bgcolor
 
-    def _printchar(self, char, invert=False):
+    def tabsize(self, value=None):
+        if value is not None:
+            self.tab = value
+        return self.tab
+
+    def _gchar(self, char):
+        if char == '\n':
+            self.cpos = 0
+        elif char == '\t':
+            nspaces = self.tab - (self.cpos % self.tab)
+            if nspaces == 0:
+                nspaces = self.tab
+            while nspaces:
+                nspaces -= 1
+                self._printchar(' ', recurse=True)
+            self.glyph = None  # All done
+            return
+        super()._get_char(char)
+        
+    def _printchar(self, char, invert=False, recurse=False):
         #print('Writer.text_row 1 = ', Writer.text_row)
-        self._get_char(char)
+        if recurse:
+            self._get_char(char)
+        else:
+            self._gchar(char)
         #print('Writer.text_row 2 = ', Writer.text_row)
         if self.glyph is None:
             return  # All done
@@ -212,3 +257,4 @@ class CWriter(Writer):
             if drow >= self.screenheight or drow < 0:
                 break
         Writer.text_col += -char_width if usd else char_width
+        self.cpos += 1

SSD1306/writer_tests.py

@@ -44,8 +44,9 @@ def inverse(use_spi=False, soft=True):
     square_side = 10
     ssd.fill_rect(rhs - square_side, 0, square_side, square_side, 1)
 
-    CWriter.set_textpos(0, 0)  # In case previous tests have altered it
+    Writer.set_textpos(0, 0)  # In case previous tests have altered it
-    wri = CWriter(ssd, freesans20, verbose=False)
+    Writer.set_clip(False, False, False)  # Char wrap
+    wri = Writer(ssd, freesans20, verbose=False)
     wri.printstring('Sunday\n')
     wri.printstring('12 Aug 2018\n')
     wri.printstring('10.30am', True)  # Inverse text
@@ -59,6 +60,7 @@ def scroll(use_spi=False, soft=True):
     ssd.fill_rect(rhs - square_side, 0, square_side, square_side, 1)
 
     Writer.set_textpos(0, 0)  # In case previous tests have altered it
+    Writer.set_clip(False, False, False)  # Char wrap
     wri = Writer(ssd, freesans20, verbose=False)
     wri.printstring('Sunday\n')
     wri.printstring('12 Aug 2018\n')
@@ -77,6 +79,7 @@ def usd_scroll(use_spi=False, soft=True):
     # Only CWriter can do usd
     CWriter.invert_display()
     CWriter.set_textpos(HEIGHT - 1, WIDTH - 1)
+    CWriter.set_clip(False, False, False)  # Char wrap
     wri = CWriter(ssd, freesans20, verbose=False)
 
     wri.printstring('Sunday\n')
@@ -97,6 +100,7 @@ def usd(use_spi=False, soft=True):
     # Only CWriter can do usd
     CWriter.invert_display()
     CWriter.set_textpos(HEIGHT - 1, WIDTH - 1)
+    CWriter.set_clip(False, False, False)  # Char wrap
     wri = CWriter(ssd, freesans20, verbose=False)
     wri.printstring('Sunday\n')
     wri.printstring('12 Aug 2018\n')
@@ -107,27 +111,29 @@ def usd(use_spi=False, soft=True):
 def rjust(use_spi=False, soft=True):
     ssd = setup(use_spi, soft)  # Create a display instance
     Writer.set_textpos(0, 0)  # Previous tests may have altered it
+    Writer.set_clip(False, False, False)  # Char wrap
     wri = Writer(ssd, freesans20, verbose=False)
 
     my_str = 'Sunday\n'
     l = wri.stringlen(my_str)
-    CWriter.set_textpos(col = WIDTH - l)
+    Writer.set_textpos(col = WIDTH - l)
     wri.printstring(my_str)
 
     my_str = '12 Aug 2018\n'
     l = wri.stringlen(my_str)
-    CWriter.set_textpos(col = WIDTH - l)
+    Writer.set_textpos(col = WIDTH - l)
     wri.printstring(my_str)
 
     my_str = '10.30am'
     l = wri.stringlen(my_str)
-    CWriter.set_textpos(col = WIDTH - l)
+    Writer.set_textpos(col = WIDTH - l)
     wri.printstring(my_str)
     ssd.show()
 
 def fonts(use_spi=False, soft=True):
     ssd = setup(use_spi, soft)  # Create a display instance
     Writer.set_textpos(0, 0)  # In case previous tests have altered it
+    Writer.set_clip(False, False, False)  # Char wrap
     wri = Writer(ssd, freesans20, verbose=False)
     wri_f = Writer(ssd, fixed, verbose=False)
     wri_f.printstring('Sunday\n')
@@ -135,17 +141,51 @@ def fonts(use_spi=False, soft=True):
     wri.printstring('10.30am')
     ssd.show()
 
+def tabs(use_spi=False, soft=True):
+    ssd = setup(use_spi, soft)  # Create a display instance
+    CWriter.set_textpos(0, 0)  # In case previous tests have altered it
+    CWriter.set_clip(False, False, False)  # Char wrap
+    wri = CWriter(ssd, fixed, verbose=False)
+    wri.printstring('1\t2\n')
+    wri.printstring('111\t22\n')
+    wri.printstring('1111\t1')
+    ssd.show()
+
+def usd_tabs(use_spi=False, soft=True):
+    ssd = setup(use_spi, soft)  # Create a display instance
+    CWriter.invert_display()
+    CWriter.set_textpos(HEIGHT - 1, WIDTH - 1)
+    CWriter.set_clip(False, False, False)  # Char wrap
+    wri = CWriter(ssd, fixed, verbose=False)
+    wri.printstring('1\t2\n')
+    wri.printstring('111\t22\n')
+    wri.printstring('1111\t1')
+    ssd.show()
+    CWriter.invert_display(False)  # For subsequent tests
+
+def wrap(use_spi=False, soft=True):
+    ssd = setup(use_spi, soft)  # Create a display instance
+    CWriter.set_textpos(0, 0)  # In case previous tests have altered it
+    CWriter.set_clip(False, False, True)  # Word wrap
+    wri = CWriter(ssd, freesans20, verbose=False)
+    wri.printstring('the quick brown fox jumps over')
+    ssd.show()
+
 tstr = '''Test assumes a 128*64 (w*h) display. Edit WIDTH and HEIGHT in ssd1306_setup.py for others.
 Device pinouts are comments in ssd1306_setup.py.
 All tests take two boolean args:
 use_spi = False. Set True for SPI connected device
 soft=True set False to use hardware I2C/SPI. Hardware option currently fails with official SSD1306 driver.
+
 Available tests:
 inverse() Show black on white text.
 scroll() Illustrate scrolling
 usd() Upside-down display.
 usd_scroll() Upside-down scroll test.
 rjust() Right justification.
-fonts() Two fonts.'''
+fonts() Two fonts.
+tabs() Tab stops.
+usd_tabs() Upside-down tabs.
+wrap() Word wrapping'''
 
 print(tstr)