fix position desync on track change, improve address search, check playback address twice, add SPOTIFY_API_DEBUG property, version 1.1.2

Author: LabyStudio

README.md

@@ -23,7 +23,7 @@ repositories {
 }
 
 dependencies {
-    implementation 'com.github.LabyStudio:java-spotify-api:1.1.1:all'
+    implementation 'com.github.LabyStudio:java-spotify-api:1.1.2:all'
 }
 ```
 

build.gradle

@@ -4,7 +4,7 @@ plugins {
 }
 
 group 'de.labystudio'
-version '1.1.1'
+version '1.1.2'
 
 compileJava {
     sourceCompatibility = '1.8'

src/main/java/de/labystudio/spotifyapi/platform/windows/WinSpotifyAPI.java

@@ -103,14 +103,17 @@ private void updatePosition(int position) {
             return;
         }
 
-        // Update position known state
+        // The position is known if the song is currently paused
+        // or if the position has changed during the runtime of the program.
+        // Because the position is updated when the track initializes, it could be that the position is not known yet.
         this.positionKnown = this.currentPosition != -1 || !this.isPlaying;
+
+        // Update position
         this.currentPosition = position;
+        this.lastTimePositionUpdated = System.currentTimeMillis();
 
+        // Fire on position changed if the position is known
         if (this.positionKnown) {
-            this.lastTimePositionUpdated = System.currentTimeMillis();
-
-            // Fire on position changed
             this.listeners.forEach(listener -> listener.onPositionChanged(position));
         }
     }

src/main/java/de/labystudio/spotifyapi/platform/windows/api/WinProcess.java

@@ -154,7 +154,7 @@ public long findInMemory(long minAddress, long maxAddress, byte[] searchBytes, S
         int index = 0;
         while (cursor < maxAddress) {
             long target = this.findInMemory(cursor, maxAddress, searchBytes);
-            if (condition.matches(target, index)) {
+            if (target == -1 || condition.matches(target, index)) {
                 return target;
             }
             cursor = target + 1;
@@ -180,6 +180,34 @@ public boolean hasBytes(long address, int... bytes) {
         return true;
     }
 
+    /**
+     * Check if the given bytes are at the given address.
+     *
+     * @param address The address to check.
+     * @param bytes   The bytes to check.
+     * @return True if the bytes are at the given address.
+     */
+    public boolean hasBytes(long address, byte[] bytes) {
+        byte[] chunk = this.readBytes(address, bytes.length);
+        for (int i = 0; i < chunk.length; i++) {
+            if (chunk[i] != bytes[i]) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    /**
+     * Check if the given text is at the given address.
+     *
+     * @param address The address to check.
+     * @param text    The text to check.
+     * @return True if the text is at the given address.
+     */
+    public boolean hasText(long address, String text) {
+        return this.hasBytes(address, text.getBytes());
+    }
+
     /**
      * Find the address of a text inside the memory.
      * If there are multiple matches of the text, the given index will be used to select the correct one.

src/main/java/de/labystudio/spotifyapi/platform/windows/api/spotify/SpotifyProcess.java

@@ -10,7 +10,15 @@
  */
 public class SpotifyProcess extends WinProcess {
 
-    private static final boolean DEBUG = false;
+    private static final boolean DEBUG = System.getProperty("SPOTIFY_API_DEBUG") != null;
+
+    // Spotify track id
+    private static final String CHROME_ELF_DLL = "chrome_elf.dll";
+    private static final String PREFIX_SPOTIFY_TRACK = "spotify:track:";
+    private static final long OFFSET_CHROME_ELF_2 = 4871;
+    private static final long OFFSET_TRACK_ID = 105700;
+
+    // Spotify playback
     private static final byte[] PREFIX_CONTEXT = new byte[]{0x63, 0x6F, 0x6E, 0x74, 0x65, 0x78, 0x74};
 
     private final long addressTrackId;
@@ -36,14 +44,11 @@ public SpotifyProcess() {
         long timeScanStart = System.currentTimeMillis();
 
         // Find address of track id (Located in the chrome_elf.dll module)
-        this.addressTrackId = this.findAddressOfText(
-                this.maxContentAddress / 2,
-                "spotify:track:",
-                (address, index) -> this.hasBytes(
-                        address + 37,
-                        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
-                )
-        );
+        this.addressTrackId = this.findAddressUsingRules(new SearchRule(CHROME_ELF_DLL, (address, index)
+                -> this.hasText(address + OFFSET_CHROME_ELF_2, CHROME_ELF_DLL)
+                && this.hasText(address + OFFSET_TRACK_ID, PREFIX_SPOTIFY_TRACK)
+        )) + OFFSET_TRACK_ID;
+
         if (this.addressTrackId == -1 || !this.isTrackIdValid(this.getTrackId())) {
             throw new IllegalStateException("Could not find track id in memory");
         }
@@ -67,13 +72,17 @@ public SpotifyProcess() {
         if (this.addressPlayBack == -1) {
             throw new IllegalStateException("Could not find playback in memory");
         }
+
+        // Create the playback accessor with the found address
+        this.playbackAccessor = new PlaybackAccessor(this, this.addressPlayBack);
+        if (!this.playbackAccessor.isValid()) {
+            throw new IllegalStateException("Could not create playback accessor");
+        }
+
         if (DEBUG) {
             System.out.println("Found playback address at: " + Long.toHexString(this.addressPlayBack));
             System.out.println("Scanning took " + (System.currentTimeMillis() - timeScanStart) + "ms");
         }
-
-        // Create the playback accessor with the found address
-        this.playbackAccessor = new PlaybackAccessor(this, this.addressPlayBack);
     }
 
     /**