Update theme guide color.

feature/media-send/src/main/java/org/signal/mediasend/screens/edit/image/ImageEditor.kt

@@ -66,6 +66,9 @@ internal fun ImageEditor(
   // Masks everything outside the image, so it has to match the surface the editor is drawn on to read as a background.
   val blackoutColor = MaterialTheme.colorScheme.surface.toArgb()
 
+  // Crop thumbs and selection guides are light-on-dark by default, which disappears against a light surface.
+  val decorationColor = MaterialTheme.colorScheme.onSurface.toArgb()
+
   DisposableEffect(state) {
     state.attach()
     onDispose { state.detach() }
@@ -96,6 +99,7 @@ internal fun ImageEditor(
       val nativeCanvas = drawContext.canvas.nativeCanvas
       val rendererContext = state.getOrCreateRendererContext(context, nativeCanvas)
       rendererContext.setBlackoutColor(blackoutColor)
+      rendererContext.setDecorationColor(decorationColor)
       rendererContext.save()
       try {
         rendererContext.canvasMatrix.initial(state.viewMatrix)

lib/image-editor/src/main/java/org/signal/imageeditor/core/RendererContext.java

@@ -57,6 +57,10 @@ public final class RendererContext {
   @Nullable
   private Integer blackoutColor;
 
+  @ColorInt
+  @Nullable
+  private Integer decorationColor;
+
   private List<EditorElement> children = Collections.emptyList();
   private Paint               maskPaint;
 
@@ -123,6 +127,22 @@ public final class RendererContext {
     return blackoutColor == null ? modelColor : ColorUtils.setAlphaComponent(blackoutColor, Color.alpha(modelColor));
   }
 
+  /**
+   * Overrides the color the editor draws its chrome -- crop thumbs, guides -- with, for a caller whose background is
+   * not always dark. Pass null to fall back to the default light-on-dark chrome.
+   */
+  public void setDecorationColor(@ColorInt @Nullable Integer decorationColor) {
+    this.decorationColor = decorationColor;
+  }
+
+  /**
+   * Resolves a decoration color against any override set for this render, preserving the alpha the caller baked in.
+   */
+  @ColorInt
+  public int resolveDecorationColor(@ColorInt int defaultColor) {
+    return decorationColor == null ? defaultColor : ColorUtils.setAlphaComponent(decorationColor, Color.alpha(defaultColor));
+  }
+
   /**
    * Persist the current state on to a stack, must be complimented by a call to {@link #restore()}.
    */

lib/image-editor/src/main/java/org/signal/imageeditor/core/renderers/CropAreaRenderer.java

@@ -50,7 +50,7 @@ public final class CropAreaRenderer implements Renderer {
     final int thickness = resources.getDimensionPixelSize(R.dimen.crop_area_renderer_edge_thickness);
     final int size      = (int) Math.min(resources.getDimensionPixelSize(R.dimen.crop_area_renderer_edge_size), Math.min(dst.width(), dst.height()) / 3f - 10);
 
-    paint.setColor(ResourcesCompat.getColor(resources, R.color.crop_area_renderer_edge_color, null));
+    paint.setColor(rendererContext.resolveDecorationColor(ResourcesCompat.getColor(resources, R.color.crop_area_renderer_edge_color, null)));
 
     rendererContext.canvasMatrix.setToIdentity();
     screenClipPath.reset();

lib/image-editor/src/main/java/org/signal/imageeditor/core/renderers/OvalGuideRenderer.java

@@ -38,7 +38,7 @@ public final class OvalGuideRenderer implements Renderer {
     float   halfStroke = stroke / 2f;
 
     this.paint.setStrokeWidth(stroke);
-    paint.setColor(ContextCompat.getColor(context, ovalGuideColor));
+    paint.setColor(rendererContext.resolveDecorationColor(ContextCompat.getColor(context, ovalGuideColor)));
 
     rendererContext.mapRect(dst, Bounds.FULL_BOUNDS);
     dst.set(dst.left + halfStroke, dst.top + halfStroke, dst.right - halfStroke, dst.bottom - halfStroke);

lib/image-editor/src/main/java/org/signal/imageeditor/core/renderers/SelectedElementGuideRenderer.kt

@@ -58,6 +58,9 @@ class SelectedElementGuideRenderer : Renderer {
   private fun performRender(rendererContext: RendererContext) {
     rendererContext.save()
 
+    guidePaint.color = rendererContext.resolveDecorationColor(Color.WHITE)
+    circlePaint.color = rendererContext.resolveDecorationColor(Color.WHITE)
+
     rendererContext.canvasMatrix.setToIdentity()
 
     path.reset()