java: working on measure function stuff

DioxusLabs · Sep 3, 2024 · 765ccd2 · 765ccd2
1 parent 59a793f
commit 765ccd2
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Showing 7 changed files with 170 additions and 2 deletions.
diff --git a/bindings/java/java/examples/java/com/dioxuslabs/taffy/Measure.java b/bindings/java/java/examples/java/com/dioxuslabs/taffy/Measure.java
@@ -0,0 +1,75 @@
+package com.dioxuslabs.taffy;
+
+import com.dioxuslabs.taffy.common.Image.ImageContext;
+import com.dioxuslabs.taffy.common.Text;
+import com.dioxuslabs.taffy.common.Text.FontMetrics;
+import com.dioxuslabs.taffy.common.Text.TextContext;
+import com.dioxuslabs.taffy.enums.Display;
+import com.dioxuslabs.taffy.enums.FlexDirection;
+import com.dioxuslabs.taffy.geom.Size;
+import com.dioxuslabs.taffy.geom.measure.AvailableSpace;
+import com.dioxuslabs.taffy.geom.measure.Dimension;
+import com.dioxuslabs.taffy.style.Style;
+
+import java.util.List;
+
+import static com.dioxuslabs.taffy.common.Image.imageMeasureFunction;
+import static com.dioxuslabs.taffy.common.Text.LOREM_IPSUM;
+import static com.dioxuslabs.taffy.common.Text.textMeasureFunction;
+
+/**
+ * Equivalent of taffy/examples/measure.rs
+ */
+public class Measure {
+    public static Size<Float> measureFunction(
+            Size<Float> knownDimensions,
+            Size<AvailableSpace> availableSpace,
+            Object nodeContext,
+            FontMetrics fontMetrics
+    ) {
+        if (knownDimensions.bothAxisDefined()) {
+            return new Size<>(knownDimensions.width(), knownDimensions.height());
+        }
+
+        if (nodeContext instanceof TextContext nc) {
+            return textMeasureFunction(knownDimensions, availableSpace, nc, fontMetrics);
+        } else if (nodeContext instanceof ImageContext nc) {
+            return imageMeasureFunction(knownDimensions, nc);
+        } else {
+            return Size.zero(Float.class);
+        }
+    }
+
+    public static void main(String[] args) {
+        TaffyTree taffy = new TaffyTree();
+
+        FontMetrics fontMetrics = new FontMetrics(10f, 10f);
+
+        long textNode = taffy.newLeafWithContext(
+                Style.def(),
+                new TextContext(LOREM_IPSUM, Text.WritingMode.HORIZONTAL)
+        );
+
+        long imageNode = taffy.newLeafWithContext(
+                Style.def(),
+                new ImageContext(400f, 300f)
+        );
+
+        long root = taffy.newWithChildren(
+                Style.builder()
+                        .display(Display.FLEX)
+                        .flexDirection(FlexDirection.COLUMN)
+                        .size(new Size<>(Dimension.length(200), Dimension.auto())),
+                List.of(textNode, imageNode)
+        );
+
+        // Compute layout and print result
+        taffy.computeLayoutWithMeasure(
+                root,
+                Size.maxContentAvailableSize()
+                // todo measure func
+        );
+
+        taffy.printTree(root);
+    }
+}
diff --git a/bindings/java/java/examples/java/com/dioxuslabs/taffy/common/Text.java b/bindings/java/java/examples/java/com/dioxuslabs/taffy/common/Text.java
@@ -46,7 +46,53 @@ public static Size<Float> textMeasureFunction(
         AtomicInteger maxLineLength = new AtomicInteger();
         Arrays.stream(words).forEach(line -> maxLineLength.addAndGet(line.length()));
 
-        float inlineSize =
-                knownDimensions.getAbs(inlineAxis)
+        Float abs = knownDimensions.getAbs(inlineAxis);
+        float inlineSize;
+        if (abs == null) {
+            AvailableSpace as = availableSpace.getAbs(inlineAxis);
+            if (as.isMinContent()) {
+                inlineSize = minLineLength * fontMetrics.charWidth;
+            } else if (as.isMaxContent()) {
+                inlineSize = maxLineLength.get() * fontMetrics.charWidth;
+            } else {
+                inlineSize = Math.max(Math.min(as.val(), maxLineLength.get() * fontMetrics.charWidth), minLineLength * fontMetrics.charWidth);
+            }
+        } else {
+            inlineSize = abs;
+        }
+
+        abs = knownDimensions.getAbs(blockAxis);
+        float blockSize;
+        if (abs == null) {
+            int inlineLineLength = (int) Math.floor(inlineSize / fontMetrics.charWidth);
+            int lineCount = 1;
+            int currentLineLength = 0;
+
+            for (String word : words) {
+                if (currentLineLength == 0) {
+                    // first word
+                    currentLineLength = word.length();
+                } else if (currentLineLength + word.length() + 1 > inlineLineLength) {
+                    // every word past the first needs to check for line length including the space between words
+                    // note: a real implementation of this should handle whitespace characters other than ' '
+                    // and do something more sophisticated for long words
+                    lineCount += 1;
+                    currentLineLength = word.length();
+                } else {
+                    // add the word and a space
+                    currentLineLength += word.length() + 1;
+                }
+            }
+
+            blockSize = lineCount * fontMetrics.charHeight;
+        } else {
+            blockSize = abs;
+        }
+
+        if (textContext.writingMode == WritingMode.HORIZONTAL) {
+            return new Size<>(inlineSize, blockSize);
+        } else {
+            return new Size<>(blockSize, inlineSize);
+        }
     }
 }
diff --git a/bindings/java/java/src/main/java/com/dioxuslabs/taffy/MeasureFunction.java b/bindings/java/java/src/main/java/com/dioxuslabs/taffy/MeasureFunction.java
@@ -0,0 +1,15 @@
+package com.dioxuslabs.taffy;
+
+import com.dioxuslabs.taffy.geom.Size;
+import com.dioxuslabs.taffy.geom.measure.AvailableSpace;
+import com.dioxuslabs.taffy.style.Style;
+
+public interface MeasureFunction {
+    Size<Float> measure(
+            Size<Float> knownDimensions,
+            Size<AvailableSpace> availableSpace,
+            long nodeId,
+            Object nodeContext,
+            Style style
+    );
+}
diff --git a/bindings/java/java/src/main/java/com/dioxuslabs/taffy/TaffyTree.java b/bindings/java/java/src/main/java/com/dioxuslabs/taffy/TaffyTree.java
@@ -10,6 +10,7 @@
 
 public class TaffyTree {
     public final long ptr;
+    public Object context;
 
     public TaffyTree() {
         this.ptr = nvNewTaffyTree();
@@ -31,6 +32,11 @@ public long newLeaf(Style style) {
         return nvNewLeaf(this.ptr, style);
     }
 
+    public long newLeafWithContext(Style style, Object context) {
+        this.context = context;
+        return nvNewLeaf(this.ptr, style);
+    }
+
     public long newWithChildren(Style style, List<Long> children) {
         return nvNewWithChildren(this.ptr, style, children);
     }

diff --git a/bindings/java/java/src/main/java/com/dioxuslabs/taffy/geom/Size.java b/bindings/java/java/src/main/java/com/dioxuslabs/taffy/geom/Size.java
@@ -35,6 +35,8 @@ public static <T> Size<T> length(Class<T> clazz, float width, float height) {
             return (Size<T>) lengthLengthPercentage(width, height);
         } else if (clazz == LengthPercentageAuto.class) {
             return (Size<T>) lengthLengthPercentageAuto(width, height);
+        } else if (clazz == Float.class) {
+            return (Size<T>) new Size<>(width, height);
         }
         return null;
     }
@@ -214,4 +216,8 @@ public String toString() {
     public T getAbs(AbsoluteAxis axis) {
         return axis == AbsoluteAxis.HORIZONTAL ? width : height;
     }
+
+    public boolean bothAxisDefined() {
+        return width != null && height != null;
+    }
 }
diff --git a/bindings/java/java/src/main/java/com/dioxuslabs/taffy/geom/measure/AvailableSpace.java b/bindings/java/java/src/main/java/com/dioxuslabs/taffy/geom/measure/AvailableSpace.java
@@ -28,4 +28,20 @@ public boolean equals(Object obj) {
         }
         return type == as.type && value == as.value;
     }
+
+    public boolean isDefinite() {
+        return type == 0;
+    }
+
+    public boolean isMinContent() {
+        return type == 1;
+    }
+
+    public boolean isMaxContent() {
+        return type == 2;
+    }
+
+    public float val() {
+        return value;
+    }
 }
diff --git a/bindings/java/java/src/main/java/com/dioxuslabs/taffy/style/Style.java b/bindings/java/java/src/main/java/com/dioxuslabs/taffy/style/Style.java
@@ -65,6 +65,10 @@ public static Style builder() {
         return new Style();
     }
 
+    public static Style def() {
+        return new Style();
+    }
+
     public Style display(Display display) {
         this.display = display;
         return this;