Merge pull request #8 from bastienlc/dev

Add support for line breaks

README.md

@@ -197,6 +197,8 @@ pip install -e .
     * Add test and lint to CI.
 * 2.2.0
     * Support PDFs with pages of different sizes.
+* 2.2.1
+    * Support line breaks in text watermark.
 
 ## License
 

src/pdf_watermark/draw.py

@@ -5,7 +5,12 @@
 from reportlab.pdfgen import canvas
 
 from pdf_watermark.options import Alignments, DrawingOptions, GridOptions, InsertOptions
-from pdf_watermark.utils import change_base, draw_centered_image, fit_image
+from pdf_watermark.utils import (
+    change_base,
+    draw_centered_image,
+    draw_centered_string_with_line_breaks,
+    fit_image,
+)
 
 
 def draw_one_watermark(
@@ -20,7 +25,8 @@ def draw_one_watermark(
     x_prime, y_prime = change_base(x, y, rotation_matrix)
 
     if drawing_options.text is not None:
-        watermark.drawCentredString(
+        draw_centered_string_with_line_breaks(
+            watermark,
             x_prime,
             y_prime,
             drawing_options.text,

src/pdf_watermark/utils.py

@@ -29,6 +29,22 @@ def draw_centered_image(
     )
 
 
+def draw_centered_string_with_line_breaks(
+    watermark: canvas.Canvas,
+    x: float,
+    y: float,
+    text: str,
+):
+    text_lines = text.split(r"\n")
+    line_height = (
+        watermark._leading
+    )  # line height is set when setting the font of the canvas
+    y += (len(text_lines) - 1) * line_height / 2  # also center the text vertically
+    for line in text_lines:
+        watermark.drawCentredString(x, y, line)
+        y -= watermark._leading
+
+
 def change_base(x: float, y: float, rotation_matrix: np.ndarray) -> Tuple[float, float]:
     # Since we rotated the original coordinates system, use the inverse of the rotation matrix
     # (which is the transposed matrix) to get the coordinates we have to draw at

tests/test_add_watermark_from_options.py

@@ -18,7 +18,12 @@
 
 INPUT = "tests/fixtures/input.pdf"
 OUTPUT = "output.pdf"
-FIXTURES = ["tests/fixtures/0.pdf", "tests/fixtures/1.pdf"]
+FIXTURES = [
+    "tests/fixtures/0.pdf",
+    "tests/fixtures/1.pdf",
+    "tests/fixtures/2.pdf",
+    "tests/fixtures/3.pdf",
+]
 
 
 @pytest.fixture(autouse=True)
@@ -39,7 +44,19 @@ def cleanup():
         image_scale=DEFAULTS.image_scale,
         save_as_image=DEFAULTS.save_as_image,
         dpi=DEFAULTS.dpi,
-    )
+    ),
+    DrawingOptions(
+        watermark=r"watermark\nwith\nline\nbreaks",
+        opacity=DEFAULTS.opacity,
+        angle=DEFAULTS.angle,
+        text_color=DEFAULTS.text_color,
+        text_font=DEFAULTS.text_font,
+        text_size=DEFAULTS.text_size,
+        unselectable=DEFAULTS.unselectable,
+        image_scale=DEFAULTS.image_scale,
+        save_as_image=DEFAULTS.save_as_image,
+        dpi=DEFAULTS.dpi,
+    ),
 ]
 
 FILES_OPTIONS_FIXTURES = [FilesOptions(INPUT, OUTPUT)]