From ab64fbdd2dab56c6db839f68b466284fb7698d27 Mon Sep 17 00:00:00 2001
From: dankito <git@dankito.net>
Date: Mon, 14 Mar 2022 02:30:07 +0100
Subject: [PATCH] Implemented inverting colors

---
 .../codinux/banking/epcqrcode/EpcQrCode.kt    |  8 ++--
 .../epcqrcode/EpcQrCodeStringFormatter.kt     | 38 ++++++++++++++-----
 2 files changed, 32 insertions(+), 14 deletions(-)

diff --git a/EpcQrCode/src/commonMain/kotlin/net/codinux/banking/epcqrcode/EpcQrCode.kt b/EpcQrCode/src/commonMain/kotlin/net/codinux/banking/epcqrcode/EpcQrCode.kt
index ed79c96..6a8dc0b 100644
--- a/EpcQrCode/src/commonMain/kotlin/net/codinux/banking/epcqrcode/EpcQrCode.kt
+++ b/EpcQrCode/src/commonMain/kotlin/net/codinux/banking/epcqrcode/EpcQrCode.kt
@@ -41,12 +41,12 @@ open class EpcQrCode(
   }
 
 
-  open fun qrCodeAsString(): String {
-    return EpcQrCodeStringFormatter().asString(this)
+  open fun qrCodeAsString(invertColors: Boolean = false): String {
+    return EpcQrCodeStringFormatter().asString(this, invertColors)
   }
 
-  open fun qrCodeAsSmallString(): String {
-    return EpcQrCodeStringFormatter().asSmallString(this)
+  open fun qrCodeAsSmallString(invertColors: Boolean = false): String {
+    return EpcQrCodeStringFormatter().asSmallString(this, invertColors)
   }
 
 
diff --git a/EpcQrCode/src/commonMain/kotlin/net/codinux/banking/epcqrcode/EpcQrCodeStringFormatter.kt b/EpcQrCode/src/commonMain/kotlin/net/codinux/banking/epcqrcode/EpcQrCodeStringFormatter.kt
index 0b88e94..24afaf3 100644
--- a/EpcQrCode/src/commonMain/kotlin/net/codinux/banking/epcqrcode/EpcQrCodeStringFormatter.kt
+++ b/EpcQrCode/src/commonMain/kotlin/net/codinux/banking/epcqrcode/EpcQrCodeStringFormatter.kt
@@ -2,7 +2,21 @@ package net.codinux.banking.epcqrcode
 
 open class EpcQrCodeStringFormatter {
 
-  open fun asString(epcQrCode: EpcQrCode): String {
+  companion object {
+    const val BitIsSetColor = "█"
+
+    const val BitIsNotSetColor = " "
+
+    const val SmallSizeUpperBitSetColor = "▀"
+
+    const val SmallSizeLowerBitSetColor = "▄"
+
+  }
+
+
+  open fun asString(epcQrCode: EpcQrCode, invertColors: Boolean = false): String {
+    val bitIsSetColor = if (invertColors) BitIsNotSetColor + BitIsNotSetColor else BitIsSetColor + BitIsSetColor
+    val bitIsNotSetColor = if (invertColors) BitIsSetColor + BitIsSetColor else BitIsNotSetColor + BitIsNotSetColor
     val height = epcQrCode.height
     val width = epcQrCode.width
     val string = StringBuilder(height * width)
@@ -10,9 +24,9 @@ open class EpcQrCodeStringFormatter {
     for (y in 1 until height) {
       for (x in 1 until width) {
         if (isBitSet(epcQrCode, x, y)) {
-          string.append("██")
+          string.append(bitIsSetColor)
         } else {
-          string.append("  ")
+          string.append(bitIsNotSetColor)
         }
       }
 
@@ -22,7 +36,11 @@ open class EpcQrCodeStringFormatter {
     return string.toString()
   }
 
-  open fun asSmallString(epcQrCode: EpcQrCode): String {
+  open fun asSmallString(epcQrCode: EpcQrCode, invertColors: Boolean = false): String {
+    val bitIsSetColor = if (invertColors) BitIsNotSetColor  else BitIsSetColor
+    val bitIsNotSetColor = if (invertColors) BitIsSetColor else BitIsNotSetColor
+    val upperBitSetColor = if (invertColors) SmallSizeLowerBitSetColor else SmallSizeUpperBitSetColor
+    val lowerBitSetColor = if (invertColors) SmallSizeUpperBitSetColor else SmallSizeLowerBitSetColor
     val height = epcQrCode.height
     val width = epcQrCode.width
     val string = StringBuilder(height * width)
@@ -34,15 +52,15 @@ open class EpcQrCodeStringFormatter {
 
         if (currentRowBit == nextRowBit) {
           if (isBitSet(currentRowBit)) {
-            string.append("█")
+            string.append(bitIsSetColor)
           } else {
-            string.append(" ")
+            string.append(bitIsNotSetColor)
           }
         } else {
           if (isBitSet(currentRowBit)) {
-            string.append("▀")
+            string.append(upperBitSetColor)
           } else {
-            string.append("▄")
+            string.append(lowerBitSetColor)
           }
         }
       }
@@ -54,9 +72,9 @@ open class EpcQrCodeStringFormatter {
       val y = height - 1
       for (x in 1 until width) {
         if (isBitSet(epcQrCode, x, y)) {
-          string.append("▀")
+          string.append(upperBitSetColor)
         } else {
-          string.append(" ")
+          string.append(bitIsNotSetColor)
         }
       }