app.py

import gradio as gr
import numpy as np
import os, random, json, spaces, torch, time

import torch
from transformers import AutoProcessor, AutoTokenizer
from longcat_image.models import LongCatImageTransformer2DModel
from longcat_image.pipelines import LongCatImagePipeline

from utils.image_utils import rescale_image
from utils.prompt_utils import polish_prompt


# Force rebuild v20
MODEL_REPO = "meituan-longcat/LongCat-Image"
MAX_SEED = np.iinfo(np.int32).max

print("Loading LongCat-Image model... v12")
text_processor = AutoTokenizer.from_pretrained(
    MODEL_REPO,
    subfolder = 'tokenizer'
)
transformer = LongCatImageTransformer2DModel.from_pretrained(
    MODEL_REPO ,
    subfolder = 'transformer',
    torch_dtype=torch.bfloat16,
    use_safetensors=True
).to("cuda")

pipe = LongCatImagePipeline.from_pretrained(
    MODEL_REPO,
    transformer=transformer,
    text_processor=text_processor
)
pipe.to("cuda", torch.bfloat16)
print("Model loaded successfully!")


@spaces.GPU
def generate_image(
    prompt,
    aspect_ratio,
    progress=gr.Progress(track_tqdm=True),
):
    """Generate an image using LongCat-Image model."""
    if not prompt.strip():
        raise gr.Error("Please enter a prompt to generate an image.")

    # Parse aspect ratio to get dimensions
    aspect_ratio_map = {
        "1:1 (1024x1024)": (1024, 1024),
        "4:3 (1024x768)": (1024, 768),
        "3:4 (768x1024)": (768, 1024),
        "16:9 (1024x576)": (1024, 576),
        "9:16 (576x1024)": (576, 1024),
    }

    width, height = aspect_ratio_map.get(aspect_ratio, (1024, 1024))

    # Generate random seed
    seed = random.randint(0, MAX_SEED)
    generator = torch.Generator().manual_seed(seed)

    progress(0.1, desc="Generating image...")

    try:
        image = pipe(
            prompt=prompt,
            negative_prompt="blurry ugly bad",
            width=width,
            height=height,
            generator=generator,
            guidance_scale=1.5,
            num_inference_steps=20,
            enable_prompt_rewrite=False
        ).images[0]

        progress(1.0, desc="Complete!")
        return image

    except Exception as e:
        raise gr.Error(f"Generation failed: {str(e)}")


# Apple-style CSS for dark theme
apple_css = """
/* Global Styles */
.gradio-container {
    max-width: 85vw !important;
    margin: 0 auto !important;
    padding: 48px 20px !important;
    font-family: -apple-system, BlinkMacSystemFont, 'Inter', 'Segoe UI', 'Roboto', sans-serif !important;
}

/* Disable all transitions globally to prevent layout shifts */
* {
    transition: none !important;
    animation: none !important;
}

/* Header */
.header-container {
    text-align: left;
    margin-bottom: 24px;
}

.main-title {
    font-size: 32px !important;
    font-weight: 600 !important;
    letter-spacing: -0.02em !important;
    line-height: 1.07 !important;
    color: #f5f5f7 !important;
    margin: 0 0 16px 0 !important;
}

/* Input Section */
.input-section {
    background: #1d1d1f;
    border-radius: 18px;
    padding: 32px;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.4);
    border: 1px solid #424245;
}

/* Textbox */
textarea {
    font-size: 17px !important;
    line-height: 1.47 !important;
    border-radius: 12px !important;
    border: 1px solid #424245 !important;
    padding: 12px 16px !important;
    background: #1d1d1f !important;
    color: #f5f5f7 !important;
    font-family: -apple-system, BlinkMacSystemFont, 'Inter', sans-serif !important;
    min-height: 200px !important;
    max-height: 400px !important;
    height: 200px !important;
    resize: vertical !important;
    overflow-y: auto !important;
    margin-bottom: 16px !important;
}

textarea:focus {
    border-color: #0071e3 !important;
    box-shadow: 0 0 0 4px rgba(0, 113, 227, 0.15) !important;
    outline: none !important;
}

textarea::placeholder {
    color: #86868b !important;
}

/* Button */
button.primary {
    font-size: 17px !important;
    font-weight: 400 !important;
    padding: 12px 32px !important;
    border-radius: 980px !important;
    background: #0071e3 !important;
    border: none !important;
    color: #ffffff !important;
    min-height: 44px !important;
    letter-spacing: -0.01em !important;
    cursor: pointer !important;
}

button.primary:hover {
    background: #0077ed !important;
}

button.primary:active {
    opacity: 0.9 !important;
}

/* Output Section */
div.output-section {
    background: #ffffff !important;
    border-radius: 18px;
    padding: 32px;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
    border: none !important;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 80vh;
    max-height: 90vh;
    will-change: auto;
    position: relative;
}

.output-section * {
    transform: none !important;
    transition: none !important;
    animation: none !important;
}

.output-section img {
    border-radius: 12px !important;
    max-width: 100% !important;
    max-height: 85vh !important;
    width: auto !important;
    height: auto !important;
    object-fit: contain !important;
    transform: none !important;
    transition: none !important;
    animation: none !important;
    backface-visibility: hidden;
    -webkit-backface-visibility: hidden;
}

/* Make progress/generation area fill more space */
.output-section > div {
    width: 100% !important;
    min-height: 75vh !important;
    max-height: 85vh !important;
    display: flex !important;
    align-items: center !important;
    justify-content: center !important;
}

.output-section > div > div {
    min-height: 75vh !important;
    max-height: 85vh !important;
    width: 100% !important;
    display: flex !important;
    align-items: center !important;
    justify-content: center !important;
}

.output-section * {
    max-width: 100% !important;
}

/* Progress */
.progress-bar {
    background: #0071e3 !important;
    border-radius: 4px !important;
}

/* Labels */
label {
    color: #f5f5f7 !important;
}

/* Dropdown */
.gr-dropdown {
    background: #1d1d1f !important;
    border: 1px solid #424245 !important;
    border-radius: 12px !important;
    color: #f5f5f7 !important;
}

select, .wrap-inner {
    background: #1d1d1f !important;
    color: #f5f5f7 !important;
    border-color: #424245 !important;
}

/* Fix column width to prevent shrinking */
.input-section {
    min-width: 550px !important;
    max-width: 550px !important;
    width: 550px !important;
    flex-shrink: 0 !important;
    flex-grow: 0 !important;
}

/* Lock the output section to fill remaining space */
.output-section {
    flex-grow: 1 !important;
    flex-shrink: 0 !important;
    flex-basis: auto !important;
}

/* Prevent Gradio columns from flexing */
.gradio-column {
    flex-shrink: 0 !important;
}

/* Stabilize row layout */
.gradio-row,
div.gradio-row,
.gradio-container .gradio-row,
.gradio-container > .gradio-row,
.gradio-container div.gradio-row {
    align-items: flex-start !important;
    flex-direction: row !important;
    display: flex !important;
    flex-wrap: nowrap !important;
    width: 100% !important;
}

/* Force columns to stay inline */
.gradio-row > .gradio-column,
.gradio-row > div {
    display: inline-flex !important;
    vertical-align: top !important;
}

/* First column - input section */
.gradio-row > .gradio-column:first-child,
.gradio-row > div:first-child {
    width: 550px !important;
    min-width: 550px !important;
    max-width: 550px !important;
    flex: 0 0 550px !important;
}

/* Second column - output section */
.gradio-row > .gradio-column:last-child,
.gradio-row > div:last-child {
    flex: 1 1 auto !important;
    min-width: 0 !important;
}

/* Hide progress indicator in input section */
.input-section .progress-container,
.input-section [class*="progress-bar"],
.input-section [class*="progress-text"],
.input-section [class*="progress-level"],
.input-section .progress,
.input-section .eta-bar {
    display: none !important;
    visibility: hidden !important;
    height: 0 !important;
    overflow: hidden !important;
}

/* Override responsive behavior */
@media (max-width: 2000px) {
    .gradio-row,
    div.gradio-row,
    .gradio-container .gradio-row,
    .gradio-container > .gradio-row {
        flex-direction: row !important;
        flex-wrap: nowrap !important;
        display: flex !important;
    }

    .gradio-row > .gradio-column,
    .gradio-row > div {
        display: inline-flex !important;
    }

    .gradio-row > .gradio-column:first-child,
    .gradio-row > div:first-child {
        width: 550px !important;
        min-width: 550px !important;
        max-width: 550px !important;
        flex: 0 0 550px !important;
    }

    .gradio-row > .gradio-column:last-child,
    .gradio-row > div:last-child {
        flex: 1 1 auto !important;
        min-width: 0 !important;
    }
}

/* Responsive text sizing only */
@media (max-width: 734px) {
    .main-title {
        font-size: 28px !important;
    }

    .gradio-container {
        padding: 32px 16px !important;
    }

    .input-section,
    .output-section {
        padding: 24px !important;
    }

    /* FORCE horizontal layout even on mobile */
    .gradio-row,
    div.gradio-row {
        flex-direction: row !important;
        flex-wrap: nowrap !important;
    }
}

/* Hide Gradio footer */
footer {
    display: none !important;
}

.footer {
    display: none !important;
}
"""

# JavaScript to force horizontal layout
js_code = """
function() {
    function forceHorizontalLayout() {
        // Set container width
        const container = document.querySelector('.gradio-container');
        if (container) {
            container.style.maxWidth = '85vw';
            container.style.width = '85vw';
        }

        // Target the main row specifically
        const mainRow = document.getElementById('main-row');
        if (mainRow) {
            mainRow.style.flexDirection = 'row';
            mainRow.style.flexWrap = 'nowrap';
            mainRow.style.display = 'flex';
            mainRow.style.width = '100%';
        }

        // Force ALL rows to stay horizontal
        const rows = document.querySelectorAll('.gradio-row');
        rows.forEach(row => {
            row.style.flexDirection = 'row';
            row.style.flexWrap = 'nowrap';
            row.style.display = 'flex';
        });

        // Target specific columns
        const inputCol = document.getElementById('input-column');
        if (inputCol) {
            inputCol.style.width = '550px';
            inputCol.style.minWidth = '550px';
            inputCol.style.maxWidth = '550px';
            inputCol.style.flex = '0 0 550px';
            inputCol.style.display = 'inline-flex';
            inputCol.style.flexDirection = 'column';
        }

        const outputCol = document.getElementById('output-column');
        if (outputCol) {
            outputCol.style.flex = '1 1 auto';
            outputCol.style.minWidth = '0';
            outputCol.style.display = 'inline-flex';
            outputCol.style.flexDirection = 'column';
        }

        // Fallback: force all column children of rows
        const columns = document.querySelectorAll('.gradio-row > .gradio-column, .gradio-row > div');
        columns.forEach((col, index) => {
            if (index === 0) {
                col.style.width = '550px';
                col.style.minWidth = '550px';
                col.style.maxWidth = '550px';
                col.style.flex = '0 0 550px';
            } else if (index === 1) {
                col.style.flex = '1 1 auto';
                col.style.minWidth = '0';
            }
            col.style.display = 'inline-flex';
        });
    }

    // Run immediately
    forceHorizontalLayout();

    // Run again after delays to override Gradio's dynamic changes
    setTimeout(forceHorizontalLayout, 100);
    setTimeout(forceHorizontalLayout, 500);
    setTimeout(forceHorizontalLayout, 1000);
    setTimeout(forceHorizontalLayout, 2000);

    // Set up mutation observer to reapply on DOM changes
    const observer = new MutationObserver(forceHorizontalLayout);
    observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });
}
"""

# Create the interface
with gr.Blocks(
    title="LongCat-Image",
    fill_height=False,
) as demo:

    # Two-column layout
    with gr.Row(equal_height=False, variant="panel", elem_id="main-row"):

        # Left column - Input controls (fixed width)
        with gr.Column(scale=0, min_width=550, elem_classes="input-section", elem_id="input-column"):

            # Title above prompt box
            gr.HTML("""
            <div class="header-container">
                <h1 class="main-title">LongCat-Image</h1>
            </div>
            """)

            prompt = gr.Textbox(
                placeholder="Describe the image you want to create...",
                value="Five shimmering goldfish weave through crevices between stones; four are red-and-white, while one is silver-white. By the pond's edge, a golden shaded British Shorthair cat watches them intently, counting on blind luck. Watercolor style.",
                lines=7,
                max_lines=7,
                label="Prompt",
                show_label=True,
                container=True,
                autoscroll=False,
            )

            aspect_ratio = gr.Dropdown(
                choices=[
                    "1:1 (1024x1024)",
                    "4:3 (1024x768)",
                    "3:4 (768x1024)",
                    "16:9 (1024x576)",
                    "9:16 (576x1024)",
                ],
                value="1:1 (1024x1024)",
                label="Aspect Ratio",
                show_label=True,
                container=True,
            )

            generate_btn = gr.Button(
                "Generate",
                variant="primary",
                size="lg",
                elem_classes="primary"
            )

        # Right column - Image output
        with gr.Column(scale=2, elem_classes="output-section", elem_id="output-column"):
            output_image = gr.Image(
                label="Result",
                show_label=False,
                type="pil",
                format="png",
            )

    # Event handlers
    generate_btn.click(
        fn=generate_image,
        inputs=[prompt, aspect_ratio],
        outputs=output_image,
        show_progress="full"
    )

    prompt.submit(
        fn=generate_image,
        inputs=[prompt, aspect_ratio],
        outputs=output_image,
        show_progress="full"
    )

    # Load event to force width with JavaScript
    demo.load(None, None, None, js=js_code)


if __name__ == "__main__":
    demo.launch(
        mcp_server=True,
        share=False,
        show_error=True,
        theme=gr.themes.Soft(
            primary_hue=gr.themes.colors.blue,
            secondary_hue=gr.themes.colors.slate,
            neutral_hue=gr.themes.colors.gray,
            spacing_size=gr.themes.sizes.spacing_lg,
            radius_size=gr.themes.sizes.radius_lg,
            text_size=gr.themes.sizes.text_md,
            font=[gr.themes.GoogleFont("Inter"), "SF Pro Display", "-apple-system", "BlinkMacSystemFont", "system-ui", "sans-serif"],
            font_mono=[gr.themes.GoogleFont("JetBrains Mono"), "SF Mono", "ui-monospace", "monospace"],
        ).set(
            body_background_fill='#000000',
            body_background_fill_dark='#000000',
            button_primary_background_fill='#0071e3',
            button_primary_background_fill_hover='#0077ed',
            button_primary_text_color='#ffffff',
            block_background_fill='#1d1d1f',
            block_background_fill_dark='#1d1d1f',
            block_border_width='0px',
            block_shadow='0 2px 12px rgba(0, 0, 0, 0.4)',
            block_shadow_dark='0 2px 12px rgba(0, 0, 0, 0.4)',
            input_background_fill='#1d1d1f',
            input_background_fill_dark='#1d1d1f',
            input_border_width='1px',
            input_border_color='#424245',
            input_border_color_dark='#424245',
            input_shadow='none',
            input_shadow_focus='0 0 0 4px rgba(0, 113, 227, 0.15)',
        ),
        css=apple_css,
    )