feat(plasma): add OCR support

src/main/java/io/github/kamitejp/platform/linux/wlroots/dependencies/slurp/Slurp.java → src/main/java/io/github/kamitejp/platform/linux/dependencies/slurp/Slurp.java

@@ -1,4 +1,4 @@
-package io.github.kamitejp.platform.linux.wlroots.dependencies.slurp;
+package io.github.kamitejp.platform.linux.dependencies.slurp;
 
 import java.util.ArrayList;
 import java.util.regex.Pattern;

src/main/java/io/github/kamitejp/platform/linux/dependencies/slurp/SlurpFade.java

@@ -0,0 +1,6 @@
+package io.github.kamitejp.platform.linux.dependencies.slurp;
+
+public enum SlurpFade {
+  FADE,
+  NO_FADE;
+}

src/main/java/io/github/kamitejp/platform/linux/dependencies/slurp/SlurpMode.java

@@ -0,0 +1,6 @@
+package io.github.kamitejp.platform.linux.dependencies.slurp;
+
+public enum SlurpMode {
+  POINT,
+  AREA;
+}

src/main/java/io/github/kamitejp/platform/linux/wlroots/dependencies/slurp/SlurpResult.java → src/main/java/io/github/kamitejp/platform/linux/dependencies/slurp/SlurpResult.java

@@ -1,4 +1,4 @@
-package io.github.kamitejp.platform.linux.wlroots.dependencies.slurp;
+package io.github.kamitejp.platform.linux.dependencies.slurp;
 
 import io.github.kamitejp.geometry.Rectangle;
 

src/main/java/io/github/kamitejp/platform/linux/kde/PlasmaPlatform.java

@@ -4,6 +4,14 @@
 import java.lang.invoke.MethodHandles;
 import java.util.List;
 
+import io.github.kamitejp.platform.PlatformOCRInitializationException;
+import io.github.kamitejp.platform.linux.dependencies.slurp.Slurp;
+import io.github.kamitejp.platform.linux.kde.dependencies.spectacle.Spectacle;
+import io.github.kamitejp.platform.linux.kde.dependencies.spectacle.SpectacleResult;
+import io.github.kamitejp.platform.linux.dependencies.slurp.SlurpFade;
+import io.github.kamitejp.platform.linux.dependencies.slurp.SlurpMode;
+import io.github.kamitejp.platform.linux.dependencies.slurp.SlurpResult;
+import io.github.kamitejp.recognition.OCREngine;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
@@ -21,6 +29,9 @@ public class PlasmaPlatform extends WaylandPlatform {
   @SuppressWarnings("unused")
   private static final Logger LOG = LogManager.getLogger(MethodHandles.lookup().lookupClass());
 
+  private Spectacle spectacle;
+  private Slurp slurp;
+
   public PlasmaPlatform() throws PlatformCreationException {
     if (!"KDE".equalsIgnoreCase(getEnvVarAsNonNullableString("XDG_CURRENT_DESKTOP"))) {
       throw new PlatformCreationException("XDG_CURRENT_DESKTOP does not match 'KDE'");
@@ -30,23 +41,90 @@ public PlasmaPlatform() throws PlatformCreationException {
   @Override
   public List<PlatformDependentFeature> getUnsupportedFeatures() {
     return List.of(
-      PlatformDependentFeature.GLOBAL_OCR,
       PlatformDependentFeature.GLOBAL_KEYBINDINGS
     );
   }
 
+  @SuppressWarnings("OverlyBroadThrowsClause")
+  @Override
+  public void initOCR(OCREngine engine) throws PlatformOCRInitializationException {
+    super.initOCR(engine);
+
+    slurp = new Slurp();
+    spectacle = new Spectacle();
+    var checkRes = checkIfDependenciesAvailable(List.of(slurp, spectacle));
+    if (checkRes.isErr()) {
+        spectacle = null;
+        throw new PlatformOCRInitializationException.MissingDependencies(checkRes.err());
+    }
+  }
+
   @Override
   public Result<Point, RecognitionOpError> getUserSelectedPoint(PointSelectionMode mode) {
     throw new UnsupportedOperationException("Not implemented");
   }
 
   @Override
   public Result<Rectangle, RecognitionOpError> getUserSelectedArea() {
-    throw new UnsupportedOperationException("Not implemented");
+    var slurpRunRes = runSlurp(SlurpMode.AREA, SlurpFade.FADE);
+    if (slurpRunRes.isErr()) {
+      return Result.Err(slurpRunRes.err());
+    }
+    return switch (slurpRunRes.get()) {
+      case SlurpResult.Area area -> Result.Ok(area.area());
+      default -> {
+        LOG.error("Received a valid but unexpected slurp result");
+        yield Result.Err(RecognitionOpError.SELECTION_FAILED);
+      }
+    };
   }
 
   @Override
   public Result<BufferedImage, RecognitionOpError> takeAreaScreenshot(Rectangle area) {
-    throw new UnsupportedOperationException("Not implemented");
+    if (spectacle == null) {
+      return Result.Err(RecognitionOpError.OCR_UNAVAILABLE);
+    }
+    return switch (spectacle.takeScreenshot(area)) {
+      case SpectacleResult.ExecutionFailed _ -> {
+        LOG.error("spectacle did not execute properly");
+        yield Result.Err(RecognitionOpError.SCREENSHOT_FAILED);
+      }
+      case SpectacleResult.Error error -> {
+        LOG.error("spectacle returned an error: {}", error::error);
+        yield Result.Err(RecognitionOpError.SCREENSHOT_FAILED);
+      }
+      case SpectacleResult.Screenshot screenshot -> Result.Ok(screenshot.screenshot());
+    };
+  }
+
+  private Result<SlurpResult, RecognitionOpError> runSlurp(SlurpMode mode, SlurpFade fade) {
+    if (slurp == null) {
+      return Result.Err(RecognitionOpError.OCR_UNAVAILABLE);
+    }
+
+    var slurpRes = slurp.getSelectionFromUser(mode, fade);
+    return switch (slurpRes) {
+      case SlurpResult.ExecutionFailed _ -> {
+        LOG.error("slurp did not execute properly");
+        yield Result.Err(RecognitionOpError.SELECTION_FAILED);
+      }
+
+      case SlurpResult.Error error -> {
+        LOG.error("slurp returned an error: {}", error::error);
+        yield Result.Err(RecognitionOpError.SELECTION_FAILED);
+      }
+
+      case SlurpResult.Cancelled _ -> Result.Err(RecognitionOpError.SELECTION_CANCELLED);
+
+      case SlurpResult.FormatDifferentFromExpected expected -> {
+        LOG.error(
+                "slurp returned malformatted result instead of expected {}",
+                expected::expected
+        );
+        yield Result.Err(RecognitionOpError.SELECTION_FAILED);
+      }
+
+      default -> Result.Ok(slurpRes);
+    };
   }
 }

src/main/java/io/github/kamitejp/platform/linux/kde/dependencies/spectacle/Spectacle.java

@@ -0,0 +1,48 @@
+package io.github.kamitejp.platform.linux.kde.dependencies.spectacle;
+
+import io.github.kamitejp.geometry.Rectangle;
+import io.github.kamitejp.image.ImageOps;
+import io.github.kamitejp.platform.BaseSimpleDependency;
+import io.github.kamitejp.platform.process.ProcessHelper;
+import io.github.kamitejp.platform.process.ProcessRunParams;
+
+import java.util.ArrayList;
+
+public class Spectacle extends BaseSimpleDependency {
+    public Spectacle() {
+        super("spectacle");
+    }
+
+    @Override
+    public boolean checkIsAvailable() {
+        var res = ProcessHelper.run(
+                ProcessRunParams.ofCmd(BIN, "-h").withTimeout(DEFAULT_AVAILABILITY_CHECK_TIMEOUT_MS)
+        );
+        return res.didComplete() && res.getStdout().startsWith("Usage: spectacle");
+    }
+
+    public SpectacleResult takeScreenshot(Rectangle area) {
+        var cmd = new ArrayList<String>();
+        cmd.add(BIN);
+        cmd.add("-bno");
+        cmd.add("/dev/stdout");
+
+        var res = ProcessHelper.runWithBinaryOutput(ProcessRunParams.ofCmd(cmd).withTimeout(3000));
+        if (!res.didComplete()) {
+            return new SpectacleResult.ExecutionFailed();
+        } else if (res.didCompleteWithError()) {
+            return new SpectacleResult.Error(res.getStderr());
+        }
+
+        var image = ImageOps.fromBytes(res.getStdout());
+        if (image == null) {
+            return new SpectacleResult.ExecutionFailed();
+        }
+
+        if (area != null) {
+          image = image.getSubimage(area.getLeft(), area.getTop(), area.getWidth(), area.getHeight());
+        }
+
+        return new SpectacleResult.Screenshot(image);
+    }
+}

src/main/java/io/github/kamitejp/platform/linux/kde/dependencies/spectacle/SpectacleResult.java

@@ -0,0 +1,10 @@
+package io.github.kamitejp.platform.linux.kde.dependencies.spectacle;
+
+public sealed interface SpectacleResult
+        permits SpectacleResult.ExecutionFailed,
+        SpectacleResult.Error,
+        SpectacleResult.Screenshot {
+  record ExecutionFailed() implements SpectacleResult {}
+  record Error(String error) implements SpectacleResult {}
+  record Screenshot(java.awt.image.BufferedImage screenshot) implements SpectacleResult {}
+}

src/main/java/io/github/kamitejp/platform/linux/wlroots/WlrootsPlatform.java

@@ -19,10 +19,10 @@
 import io.github.kamitejp.platform.linux.WaylandPlatform;
 import io.github.kamitejp.platform.linux.wlroots.dependencies.grim.Grim;
 import io.github.kamitejp.platform.linux.wlroots.dependencies.grim.GrimResult;
-import io.github.kamitejp.platform.linux.wlroots.dependencies.slurp.Slurp;
-import io.github.kamitejp.platform.linux.wlroots.dependencies.slurp.SlurpFade;
-import io.github.kamitejp.platform.linux.wlroots.dependencies.slurp.SlurpMode;
-import io.github.kamitejp.platform.linux.wlroots.dependencies.slurp.SlurpResult;
+import io.github.kamitejp.platform.linux.dependencies.slurp.Slurp;
+import io.github.kamitejp.platform.linux.dependencies.slurp.SlurpFade;
+import io.github.kamitejp.platform.linux.dependencies.slurp.SlurpMode;
+import io.github.kamitejp.platform.linux.dependencies.slurp.SlurpResult;
 import io.github.kamitejp.platform.linux.wlroots.dependencies.wlrctl.Wlrctl;
 import io.github.kamitejp.platform.linux.wlroots.dependencies.wlrctl.WlrctlResult;
 import io.github.kamitejp.recognition.OCREngine;