Adds bash script to replace the icons of an existing Eclipse

README.md

@@ -28,6 +28,26 @@ This repository contains the source for the [Eclipse UI Guidelines](https://ecli
 Build it with `mvn verify`.
 
 
+## Icon Replacement
+
+A utility script `replace_icons.sh` is provided to automate replacing icons in an existing Eclipse installation based on the `icon-mapping.json` file.
+
+**Usage:**
+```bash
+./replace_icons.sh <eclipse_plugins_dir> <mapping_json_file>
+```
+
+**Example:**
+```bash
+./replace_icons.sh /path/to/eclipse/plugins iconpacks/eclipse-dual-tone/icon-mapping.json
+```
+
+**Important:** After running the script, you **must** restart Eclipse with the following flags to ensure the icon cache is cleared and the new icons are displayed:
+```bash
+eclipse -clean -clearPersistedState
+```
+
+
 ### Making changes
 
 Please ensure that [every sentence is on a separate line](https://asciidoctor.org/docs/asciidoc-recommended-practices/#one-sentence-per-line).

replace_icons.sh

@@ -0,0 +1,90 @@
+#!/bin/bash
+
+# replace_icons.sh
+# Replaces Eclipse icons with new icons based on a mapping file.
+
+if [ "$#" -ne 2 ]; then
+    echo "Usage: $0 <eclipse_plugins_dir> <mapping_json_file>"
+    exit 1
+fi
+
+PLUGINS_DIR="$1"
+MAPPING_FILE="$2"
+# Base directory of the mapping file to find the new icons
+ICONS_BASE_DIR=$(dirname "$MAPPING_FILE")
+
+if [ ! -d "$PLUGINS_DIR" ]; then
+    echo "Error: Plugins directory $PLUGINS_DIR does not exist."
+    exit 1
+fi
+
+if [ ! -f "$MAPPING_FILE" ]; then
+    echo "Error: Mapping file $MAPPING_FILE does not exist."
+    exit 1
+fi
+
+# We need jq to parse JSON. Check if it's available.
+if ! command -v jq &> /dev/null; then
+    echo "Error: jq is required to parse the mapping file. Please install it."
+    exit 1
+fi
+
+# We need jar to update jar files.
+if ! command -v jar &> /dev/null; then
+    echo "Error: jar command is required to update JAR-based plugins. Please install a JDK."
+    exit 1
+fi
+
+# Iterate over each source icon in the mapping
+jq -r 'to_entries[] | .key + " " + (.value | join(" "))' "$MAPPING_FILE" | while read -r line; do
+    read -ra parts <<< "$line"
+    src_icon_name="${parts[0]}"
+    # Search for the source icon recursively within the ICONS_BASE_DIR
+    src_icon_path=$(find "$ICONS_BASE_DIR" -name "$src_icon_name" | head -n 1)
+
+    if [ -z "$src_icon_path" ] || [ ! -f "$src_icon_path" ]; then
+        echo "Warning: Source icon $src_icon_name not found in $ICONS_BASE_DIR. Skipping."
+        continue
+    fi
+
+    # The rest are targets
+    for target in "${parts[@]:1}"; do
+        # Target format: plugin_id/path/to/icon.svg
+        plugin_id="${target%%/*}"
+        target_relative_path="${target#*/}"
+
+        # Find the plugin in the plugins directory.
+        # It could be a folder: plugin_id_version
+        # or a jar: plugin_id_version.jar
+        plugin_path=$(find "$PLUGINS_DIR" -maxdepth 1 -name "${plugin_id}_*" | head -n 1)
+
+        if [ -z "$plugin_path" ]; then
+            echo "Warning: Plugin $plugin_id not found in $PLUGINS_DIR. Skipping $target."
+            continue
+        fi
+
+        if [ -d "$plugin_path" ]; then
+            # Folder-based plugin
+            dest_path="$plugin_path/$target_relative_path"
+            dest_dir=$(dirname "$dest_path")
+            mkdir -p "$dest_dir"
+            cp "$src_icon_path" "$dest_path"
+            echo "Replaced $target in folder: $plugin_path"
+        elif [ -f "$plugin_path" ] && [[ "$plugin_path" == *.jar ]]; then
+            # JAR-based plugin
+            # We need to update the JAR file.
+            # Using 'jar uf' or 'zip' to update the entry.
+            # Create a temporary directory to replicate the structure for the jar update
+            temp_jar_dir=$(mktemp -d)
+            mkdir -p "$temp_jar_dir/$(dirname "$target_relative_path")"
+            cp "$src_icon_path" "$temp_jar_dir/$target_relative_path"
+
+            (cd "$temp_jar_dir" && jar uf "$plugin_path" "$target_relative_path")
+
+            rm -rf "$temp_jar_dir"
+            echo "Replaced $target in JAR: $plugin_path"
+        fi
+    done
+done
+
+echo "Icon replacement completed."