From 65b433b1389b45138a2d8c97e4acbd1c80fdbfcb Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Patrick=20Ha=C3=9Fel?= <git@patrick-hassel.de>
Date: Thu, 23 Feb 2023 10:05:45 +0100
Subject: [PATCH] preview with 50% alpha

---
 .../{ImageResizer.java => ImageHelper.java}    | 18 +++++++++++++++++-
 .../de/ph87/kindermalen/tool/stamp/Stamp.java  |  2 +-
 .../ph87/kindermalen/tool/stamp/StampTool.java | 16 ++++++++--------
 3 files changed, 26 insertions(+), 10 deletions(-)
 rename src/main/java/de/ph87/kindermalen/{ImageResizer.java => ImageHelper.java} (59%)

diff --git a/src/main/java/de/ph87/kindermalen/ImageResizer.java b/src/main/java/de/ph87/kindermalen/ImageHelper.java
similarity index 59%
rename from src/main/java/de/ph87/kindermalen/ImageResizer.java
rename to src/main/java/de/ph87/kindermalen/ImageHelper.java
index 24e6fbe..8ea00a9 100644
--- a/src/main/java/de/ph87/kindermalen/ImageResizer.java
+++ b/src/main/java/de/ph87/kindermalen/ImageHelper.java
@@ -5,8 +5,24 @@ import com.mortennobel.imagescaling.ResampleOp;
 
 import java.awt.*;
 import java.awt.image.BufferedImage;
+import java.awt.image.WritableRaster;
 
-public class ImageResizer {
+public class ImageHelper {
+
+  public static BufferedImage COPY(final BufferedImage source) {
+    final BufferedImage copy = new BufferedImage(source.getWidth(), source.getHeight(), source.getType());
+    source.copyData(copy.getRaster());
+    return copy;
+  }
+
+  public static void ALPHA(final BufferedImage image, final double alpha) {
+    final WritableRaster raster = image.getAlphaRaster();
+    for (int y = 0; y < raster.getHeight(); y++) {
+      for (int x = 0; x < raster.getWidth(); x++) {
+        raster.setSample(x, y, 0, raster.getSample(x, y, 0) * alpha);
+      }
+    }
+  }
 
   public static BufferedImage RESIZE(final BufferedImage image, final int maxWidth, final int maxHeight) {
     final Point size = fitInsideBox(image, maxWidth, maxHeight);
diff --git a/src/main/java/de/ph87/kindermalen/tool/stamp/Stamp.java b/src/main/java/de/ph87/kindermalen/tool/stamp/Stamp.java
index 4887ce0..1f863e5 100644
--- a/src/main/java/de/ph87/kindermalen/tool/stamp/Stamp.java
+++ b/src/main/java/de/ph87/kindermalen/tool/stamp/Stamp.java
@@ -11,7 +11,7 @@ import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
 
-import static de.ph87.kindermalen.ImageResizer.RESIZE;
+import static de.ph87.kindermalen.ImageHelper.RESIZE;
 
 @Slf4j
 @Getter
diff --git a/src/main/java/de/ph87/kindermalen/tool/stamp/StampTool.java b/src/main/java/de/ph87/kindermalen/tool/stamp/StampTool.java
index 5b24e1b..a3e3172 100644
--- a/src/main/java/de/ph87/kindermalen/tool/stamp/StampTool.java
+++ b/src/main/java/de/ph87/kindermalen/tool/stamp/StampTool.java
@@ -13,7 +13,7 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.Objects;
 
-import static de.ph87.kindermalen.ImageResizer.RESIZE;
+import static de.ph87.kindermalen.ImageHelper.*;
 import static de.ph87.kindermalen.tool.stamp.ListHelper.SYNC;
 
 @Slf4j
@@ -36,6 +36,9 @@ public class StampTool extends Tool {
 
   private BufferedImage prepared;
 
+  @Getter
+  private BufferedImage preview;
+
   public StampTool() {
     super("Stempel");
     final List<File> files = scan(STAMPS_DIR);
@@ -86,9 +89,11 @@ public class StampTool extends Tool {
     if (this.stamp == null || stamp.getOriginal() == null) {
       return;
     }
-    this.prepared = RESIZE(stamp.getOriginal(), size, size);
+    prepared = RESIZE(stamp.getOriginal(), size, size);
+    preview = COPY(prepared);
+    ALPHA(preview, 0.5);
+    ALPHA(prepared, alpha);
     log.info("Stamp prepared: {}", stamp.getName());
-    // TODO apply alpha
   }
 
   @Override
@@ -110,9 +115,4 @@ public class StampTool extends Tool {
     destination.getGraphics().drawImage(prepared, point.intX() - prepared.getWidth() / 2, point.intY() - prepared.getHeight() / 2, null);
   }
 
-  @Override
-  public BufferedImage getPreview() {
-    return prepared;
-  }
-
 }